When EVM_ALLOW_METADATA_WRITES is set, EVM allows any operation on
metadata. Its main purpose is to allow users to freely set metadata when it
is protected by a portable signature, until an HMAC key is loaded.
However, callers of evm_verifyxattr() are not notified about metadata
changes and continue to rely on the last status returned by the function.
For example IMA, since it caches the appraisal result, will not call again
evm_verifyxattr() until the appraisal flags are cleared, and will grant
access to the file even if there was a metadata operation that made the
portable signature invalid.
This patch introduces evm_revalidate_status(), which callers of
evm_verifyxattr() can use in their xattr hooks to determine whether
re-validation is necessary and to do the proper actions. IMA calls it in
its xattr hooks to reset the appraisal flags, so that the EVM status is
re-evaluated after a metadata operation.
Lastly, this patch also adds a call to evm_reset_status() in
evm_inode_post_setattr() to invalidate the cached EVM status after a
setattr operation.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The public builtin keys do not need to be appraised by IMA as the
restriction on the IMA/EVM trusted keyrings ensures that a key can be
loaded only if it is signed with a key on the builtin or secondary
keyrings.
However, when evm_load_x509() is called, appraisal is already enabled and
a valid IMA signature must be added to the EVM key to pass verification.
Since the restriction is applied on both IMA and EVM trusted keyrings, it
is safe to disable appraisal also when the EVM key is loaded. This patch
calls evm_load_x509() inside ima_load_x509() if CONFIG_IMA_LOAD_X509 is
enabled, which crosses the normal IMA and EVM boundary.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Merge tag 'integrity-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull IMA updates from Mimi Zohar:
"In addition to loading the kernel module signing key onto the builtin
keyring, load it onto the IMA keyring as well.
Also six trivial changes and bug fixes"
* tag 'integrity-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: ensure IMA_APPRAISE_MODSIG has necessary dependencies
ima: Fix fall-through warnings for Clang
integrity: Add declarations to init_once void arguments.
ima: Fix function name error in comment.
ima: enable loading of build time generated key on .ima keyring
ima: enable signing of modules with build time generated key
keys: cleanup build time module signing keys
ima: Fix the error code for restoring the PCR value
ima: without an IMA policy loaded, return quickly
- Refactoring powerpc and arm64 kexec DT handling to common code. This
enables IMA on arm64.
- Add kbuild support for applying DT overlays at build time. The first
user are the DT unittests.
- Fix kerneldoc formatting and W=1 warnings in drivers/of/
- Fix handling 64-bit flag on PCI resources
- Bump dtschema version required to v2021.2.1
- Enable undocumented compatible checks for dtbs_check. This allows
tracking of missing binding schemas.
- DT docs improvements. Regroup the DT docs and add the example schema
and DT kernel ABI docs to the doc build.
- Convert Broadcom Bluetooth and video-mux bindings to schema
- Add QCom sm8250 Venus video codec binding schema
- Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile
Technologies Inc.
- Cleanup of DT schema type references on common properties and
standard unit properties
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Merge tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Refactor powerpc and arm64 kexec DT handling to common code. This
enables IMA on arm64.
- Add kbuild support for applying DT overlays at build time. The first
user are the DT unittests.
- Fix kerneldoc formatting and W=1 warnings in drivers/of/
- Fix handling 64-bit flag on PCI resources
- Bump dtschema version required to v2021.2.1
- Enable undocumented compatible checks for dtbs_check. This allows
tracking of missing binding schemas.
- DT docs improvements. Regroup the DT docs and add the example schema
and DT kernel ABI docs to the doc build.
- Convert Broadcom Bluetooth and video-mux bindings to schema
- Add QCom sm8250 Venus video codec binding schema
- Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile
Technologies Inc.
- Cleanup of DT schema type references on common properties and
standard unit properties
* tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits)
powerpc: If kexec_build_elf_info() fails return immediately from elf64_load()
powerpc: Free fdt on error in elf64_load()
of: overlay: Fix kerneldoc warning in of_overlay_remove()
of: linux/of.h: fix kernel-doc warnings
of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses
dt-bindings: bcm4329-fmac: add optional brcm,ccode-map
docs: dt: update writing-schema.rst references
dt-bindings: media: venus: Add sm8250 dt schema
of: base: Fix spelling issue with function param 'prop'
docs: dt: Add DT API documentation
of: Add missing 'Return' section in kerneldoc comments
of: Fix kerneldoc output formatting
docs: dt: Group DT docs into relevant sub-sections
docs: dt: Make 'Devicetree' wording more consistent
docs: dt: writing-schema: Include the example schema in the doc build
docs: dt: writing-schema: Remove spurious indentation
dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc
dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3
dt-bindings: media: video-interfaces: Drop the example
devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt
...
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break statements instead of just
letting the code fall through to the next case.
Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The original function name was ima_path_check(). The policy parsing
still supports PATH_CHECK. Commit 9bbb6cad01 ("ima: rename
ima_path_check to ima_file_check") renamed the function to
ima_file_check(), but missed modifying the function name in the
comment.
Fixes: 9bbb6cad01 ("ima: rename ima_path_check to ima_file_check").
Signed-off-by: Jiele Zhao <unclexiaole@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
In ima_restore_measurement_list(), hdr[HDR_PCR].data is pointing to a
buffer of type u8, which contains the dumped 32-bit pcr value.
Currently, only the least significant byte is used to restore the pcr
value. We should convert hdr[HDR_PCR].data to a pointer of type u32
before fetching the value to restore the correct pcr value.
Fixes: 47fdee60b4 ("ima: use ima_parse_buf() to parse measurements headers")
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Of the three LSMs that implement the security_task_getsecid() LSM
hook, all three LSMs provide the task's objective security
credentials. This turns out to be unfortunate as most of the hook's
callers seem to expect the task's subjective credentials, although
a small handful of callers do correctly expect the objective
credentials.
This patch is the first step towards fixing the problem: it splits
the existing security_task_getsecid() hook into two variants, one
for the subjective creds, one for the objective creds.
void security_task_getsecid_subj(struct task_struct *p,
u32 *secid);
void security_task_getsecid_obj(struct task_struct *p,
u32 *secid);
While this patch does fix all of the callers to use the correct
variant, in order to keep this patch focused on the callers and to
ease review, the LSMs continue to use the same implementation for
both hooks. The net effect is that this patch should not change
the behavior of the kernel in any way, it will be up to the latter
LSM specific patches in this series to change the hook
implementations and return the correct credentials.
Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA)
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The functions defined in "arch/powerpc/kexec/ima.c" handle setting up
and freeing the resources required to carry over the IMA measurement
list from the current kernel to the next kernel across kexec system call.
These functions do not have architecture specific code, but are
currently limited to powerpc.
Move remove_ima_buffer() and setup_ima_buffer() calls into
of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
Move the remaining architecture independent functions from
"arch/powerpc/kexec/ima.c" to "drivers/of/kexec.c".
Delete "arch/powerpc/kexec/ima.c" and "arch/powerpc/include/asm/ima.h".
Remove references to the deleted files and functions in powerpc and
in ima.
Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-11-nramas@linux.microsoft.com
The fields ima_buffer_addr and ima_buffer_size in "struct kimage_arch"
for powerpc are used to carry forward the IMA measurement list across
kexec system call. These fields are not architecture specific, but are
currently limited to powerpc.
arch_ima_add_kexec_buffer() defined in "arch/powerpc/kexec/ima.c"
sets ima_buffer_addr and ima_buffer_size for the kexec system call.
This function does not have architecture specific code, but is
currently limited to powerpc.
Move ima_buffer_addr and ima_buffer_size to "struct kimage".
Set ima_buffer_addr and ima_buffer_size in ima_add_kexec_buffer()
in security/integrity/ima/ima_kexec.c.
Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Will Deacon <will@kernel.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-9-nramas@linux.microsoft.com
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Merge tag 'keys-misc-20210126' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring updates from David Howells:
"Here's a set of minor keyrings fixes/cleanups that I've collected from
various people for the upcoming merge window.
A couple of them might, in theory, be visible to userspace:
- Make blacklist_vet_description() reject uppercase letters as they
don't match the all-lowercase hex string generated for a blacklist
search.
This may want reconsideration in the future, but, currently, you
can't add to the blacklist keyring from userspace and the only
source of blacklist keys generates lowercase descriptions.
- Fix blacklist_init() to use a new KEY_ALLOC_* flag to indicate that
it wants KEY_FLAG_KEEP to be set rather than passing KEY_FLAG_KEEP
into keyring_alloc() as KEY_FLAG_KEEP isn't a valid alloc flag.
This isn't currently a problem as the blacklist keyring isn't
currently writable by userspace.
The rest of the patches are cleanups and I don't think they should
have any visible effect"
* tag 'keys-misc-20210126' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
watch_queue: rectify kernel-doc for init_watch()
certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID
certs: Fix blacklist flag type confusion
PKCS#7: Fix missing include
certs: Fix blacklisted hexadecimal hash string check
certs/blacklist: fix kernel doc interface issue
crypto: public_key: Remove redundant header file from public_key.h
keys: remove trailing semicolon in macro definition
crypto: pkcs7: Use match_string() helper to simplify the code
PKCS#7: drop function from kernel-doc pkcs7_validate_trust_one
encrypted-keys: Replace HTTP links with HTTPS ones
crypto: asymmetric_keys: fix some comments in pkcs7_parser.h
KEYS: remove redundant memset
security: keys: delete repeated words in comments
KEYS: asymmetric: Fix kerneldoc
security/keys: use kvfree_sensitive()
watch_queue: Drop references to /dev/watch_queue
keys: Remove outdated __user annotations
security: keys: Fix fall-through warnings for Clang
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdfhttps://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
IMA allocates kernel virtual memory to carry forward the measurement
list, from the current kernel to the next kernel on kexec system call,
in ima_add_kexec_buffer() function. This buffer is not freed before
completing the kexec system call resulting in memory leak.
Add ima_buffer field in "struct kimage" to store the virtual address
of the buffer allocated for the IMA measurement list.
Free the memory allocated for the IMA measurement list in
kimage_file_post_load_cleanup() function.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Fixes: 7b8589cc29 ("ima: on soft reboot, save the measurement list")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
IMA allocates kernel virtual memory to carry forward the measurement
list, from the current kernel to the next kernel on kexec system call,
in ima_add_kexec_buffer() function. In error code paths this memory
is not freed resulting in memory leak.
Free the memory allocated for the IMA measurement list in
the error code paths in ima_add_kexec_buffer() function.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Fixes: 7b8589cc29 ("ima: on soft reboot, save the measurement list")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The integrity of a kernel can be verified by the boot loader on cold
boot, and during kexec, by the current running kernel, before it is
loaded. However, it is still possible that the new kernel being
loaded is older than the current kernel, and/or has known
vulnerabilities. Therefore, it is imperative that an attestation
service be able to verify the version of the kernel being loaded on
the client, from cold boot and subsequent kexec system calls,
ensuring that only kernels with versions known to be good are loaded.
Measure the kernel version using ima_measure_critical_data() early on
in the boot sequence, reducing the chances of known kernel
vulnerabilities being exploited. With IMA being part of the kernel,
this overall approach makes the measurement itself more trustworthy.
To enable measuring the kernel version "ima_policy=critical_data"
needs to be added to the kernel command line arguments.
For example,
BOOT_IMAGE=/boot/vmlinuz-5.11.0-rc3+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset ima_policy=critical_data
If runtime measurement of the kernel version is ever needed, the
following should be added to /etc/ima/ima-policy:
measure func=CRITICAL_DATA label=kernel_info
To extract the measured data after boot, the following command can be used:
grep -m 1 "kernel_version" \
/sys/kernel/security/integrity/ima/ascii_runtime_measurements
Sample output from the command above:
10 a8297d408e9d5155728b619761d0dd4cedf5ef5f ima-buf
sha256:5660e19945be0119bc19cbbf8d9c33a09935ab5d30dad48aa11f879c67d70988
kernel_version 352e31312e302d7263332d31363138372d676564623634666537383234342d6469727479
The above hex-ascii string corresponds to the kernel version
(e.g. xxd -r -p):
5.11.0-rc3-16187-gedb64fe78244-dirty
Signed-off-by: Raphael Gianotti <raphgi@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
IMA does sometimes access the inode's i_uid and compares it against the
rules' fowner. Enable IMA to handle idmapped mounts by passing down the
mount's user namespace. We simply make use of the helpers we introduced
before. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-27-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
When interacting with extended attributes the vfs verifies that the
caller is privileged over the inode with which the extended attribute is
associated. For posix access and posix default extended attributes a uid
or gid can be stored on-disk. Let the functions handle posix extended
attributes on idmapped mounts. If the inode is accessed through an
idmapped mount we need to map it according to the mount's user
namespace. Afterwards the checks are identical to non-idmapped mounts.
This has no effect for e.g. security xattrs since they don't store uids
or gids and don't perform permission checks on them like posix acls do.
Link: https://lore.kernel.org/r/20210121131959.646623-10-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() or key_alloc(),
as these only take KEY_ALLOC_* flags. KEY_FLAG_KEEP has the same value as
KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only key_create_or_update()
uses it. LSMs using the key_alloc hook don't check that flag.
KEY_FLAG_KEEP is then ignored but fortunately (again) the root user cannot
write to the blacklist keyring, so it is not possible to remove a key/hash
from it.
Fix this by adding a KEY_ALLOC_SET_KEEP flag that tells key_alloc() to set
KEY_FLAG_KEEP on the new key. blacklist_init() can then, correctly, pass
this to keyring_alloc().
We can also use this in ima_mok_init() rather than setting the flag
manually.
Note that this doesn't fix an observable bug with the current
implementation but it is required to allow addition of new hashes to the
blacklist in the future without making it possible for them to be removed.
Fixes: 734114f878 ("KEYS: Add a system blacklist keyring")
Reported-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Mickaël Salaün <mic@linux.microsoft.com>
cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Define a new critical data builtin policy to allow measuring
early kernel integrity critical data before a custom IMA policy
is loaded.
Update the documentation on kernel parameters to document
the new critical data builtin policy.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The IMA hook ima_measure_critical_data() does not support a way to
specify the source of the critical data provider. Thus, the data
measurement cannot be constrained based on the data source label
in the IMA policy.
Extend the IMA hook ima_measure_critical_data() to support passing
the data source label as an input parameter, so that the policy rule can
be used to limit the measurements based on the label.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Integrity critical data may belong to a single subsystem or it may
arise from cross subsystem interaction. Currently there is no mechanism
to group or limit the data based on certain label. Limiting and
grouping critical data based on a label would make it flexible and
configurable to measure.
Define "label:=", a new IMA policy condition, for the IMA func
CRITICAL_DATA to allow grouping and limiting measurement of integrity
critical data.
Limit the measurement to the labels that are specified in the IMA
policy - CRITICAL_DATA+"label:=". If "label:=" is not provided with
the func CRITICAL_DATA, measure all the input integrity critical data.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
A new IMA policy rule is needed for the IMA hook
ima_measure_critical_data() and the corresponding func CRITICAL_DATA for
measuring the input buffer. The policy rule should ensure the buffer
would get measured only when the policy rule allows the action. The
policy rule should also support the necessary constraints (flags etc.)
for integrity critical buffer data measurements.
Add policy rule support for measuring integrity critical data.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
IMA provides capabilities to measure file and buffer data. However,
various data structures, policies, and states stored in kernel memory
also impact the integrity of the system. Several kernel subsystems
contain such integrity critical data. These kernel subsystems help
protect the integrity of the system. Currently, IMA does not provide a
generic function for measuring kernel integrity critical data.
Define ima_measure_critical_data, a new IMA hook, to measure kernel
integrity critical data.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The original IMA buffer data measurement sizes were small (e.g. boot
command line), but the new buffer data measurement use cases have data
sizes that are a lot larger. Just as IMA measures the file data hash,
not the file data, IMA should similarly support the option for measuring
buffer data hash.
Introduce a boolean parameter to support measuring buffer data hash,
which would be much smaller, instead of the buffer itself.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
IMA functions such as ima_match_keyring(), process_buffer_measurement(),
ima_match_policy() etc. handle data specific to keyrings. Currently,
these constructs are not generic to handle any func specific data.
This makes it harder to extend them without code duplication.
Refactor the keyring specific measurement constructs to be generic and
reusable in other measurement scenarios.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
- Don't move BSS section around pointlessly in the x86 decompressor
- Refactor helper for discovering the EFI secure boot mode
- Wire up EFI secure boot to IMA for arm64
- Some fixes for the capsule loader
- Expose the RT_PROP table via the EFI test module
- Relax DT and kernel placement restrictions on ARM
+ followup fixes:
- fix the build breakage on IA64 caused by recent capsule loader changes
- suppress a type mismatch build warning in the expansion of
EFI_PHYS_ALIGN on ARM
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Merge tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Borislav Petkov:
"These got delayed due to a last minute ia64 build issue which got
fixed in the meantime.
EFI updates collected by Ard Biesheuvel:
- Don't move BSS section around pointlessly in the x86 decompressor
- Refactor helper for discovering the EFI secure boot mode
- Wire up EFI secure boot to IMA for arm64
- Some fixes for the capsule loader
- Expose the RT_PROP table via the EFI test module
- Relax DT and kernel placement restrictions on ARM
with a few followup fixes:
- fix the build breakage on IA64 caused by recent capsule loader
changes
- suppress a type mismatch build warning in the expansion of
EFI_PHYS_ALIGN on ARM"
* tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: arm: force use of unsigned type for EFI_PHYS_ALIGN
efi: ia64: disable the capsule loader
efi: stub: get rid of efi_get_max_fdt_addr()
efi/efi_test: read RuntimeServicesSupported
efi: arm: reduce minimum alignment of uncompressed kernel
efi: capsule: clean scatter-gather entries from the D-cache
efi: capsule: use atomic kmap for transient sglist mappings
efi: x86/xen: switch to efi_get_secureboot_mode helper
arm64/ima: add ima_arch support
ima: generalize x86/EFI arch glue for other EFI architectures
efi: generalize efi_get_secureboot
efi/libstub: EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER should not default to yes
efi/x86: Only copy the compressed kernel image in efi_relocate_kernel()
efi/libstub/x86: simplify efi_is_native()
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Merge tag 'integrity-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity subsystem updates from Mimi Zohar:
"Just three patches here. Other integrity changes are being upstreamed
via EFI (defines a common EFI secure and trusted boot IMA policy) and
BPF LSM (exporting the IMA file cache hash info based on inode).
The three patches included here:
- bug fix: fail calculating the file hash, when a file not opened for
read and the attempt to re-open it for read fails.
- defer processing the "ima_appraise" boot command line option to
avoid enabling different modes (e.g. fix, log) to when the secure
boot flag is available on arm.
- defines "ima-buf" as the default IMA buffer measurement template in
preparation for the builtin integrity "critical data" policy"
* tag 'integrity-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: Don't modify file descriptor mode on the fly
ima: select ima-buf template for buffer measurement
ima: defer arch_ima_get_secureboot() call to IMA init time
Commit a408e4a86b ("ima: open a new file instance if no read
permissions") already introduced a second open to measure a file when the
original file descriptor does not allow it. However, it didn't remove the
existing method of changing the mode of the original file descriptor, which
is still necessary if the current process does not have enough privileges
to open a new one.
Changing the mode isn't really an option, as the filesystem might need to
do preliminary steps to make the read possible. Thus, this patch removes
the code and keeps the second open as the only option to measure a file
when it is unreadable with the original file descriptor.
Cc: <stable@vger.kernel.org> # 4.20.x: 0014cc04e8 ima: Set file->f_mode
Fixes: 2fe5d6def1 ("ima: integrity appraisal extension")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This is in preparation to add a helper for BPF LSM programs to use
IMA hashes when attached to LSM hooks. There are LSM hooks like
inode_unlink which do not have a struct file * argument and cannot
use the existing ima_file_hash API.
An inode based API is, therefore, useful in LSM based detections like an
executable trying to delete itself which rely on the inode_unlink LSM
hook.
Moreover, the ima_file_hash function does nothing with the struct file
pointer apart from calling file_inode on it and converting it to an
inode.
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20201124151210.1081188-2-kpsingh@chromium.org
The default IMA template used for all policy rules is the value set
for CONFIG_IMA_DEFAULT_TEMPLATE if the policy rule does not specify
a template. The default IMA template for buffer measurements should be
'ima-buf' - so that the measured buffer is correctly included in the IMA
measurement log entry.
With the default template format, buffer measurements are added to
the measurement list, but do not include the buffer data, making it
difficult, if not impossible, to validate. Including 'ima-buf'
template records in the measurement list by default, should not impact
existing attestation servers without 'ima-buf' template support.
Initialize a global 'ima-buf' template and select that template,
by default, for buffer measurements.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Move the x86 IMA arch code into security/integrity/ima/ima_efi.c,
so that we will be able to wire it up for arm64 in a future patch.
Co-developed-by: Chester Lin <clin@suse.com>
Signed-off-by: Chester Lin <clin@suse.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Chester reports that it is necessary to introduce a new way to pass
the EFI secure boot status between the EFI stub and the core kernel
on ARM systems. The usual way of obtaining this information is by
checking the SecureBoot and SetupMode EFI variables, but this can
only be done after the EFI variable workqueue is created, which
occurs in a subsys_initcall(), whereas arch_ima_get_secureboot()
is called much earlier by the IMA framework.
However, the IMA framework itself is started as a late_initcall,
and the only reason the call to arch_ima_get_secureboot() occurs
so early is because it happens in the context of a __setup()
callback that parses the ima_appraise= command line parameter.
So let's refactor this code a little bit, by using a core_param()
callback to capture the command line argument, and deferring any
reasoning based on its contents to the IMA init routine.
Cc: Chester Lin <clin@suse.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Link: https://lore.kernel.org/linux-arm-kernel/20200904072905.25332-2-clin@suse.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reported-by: kernel test robot <lkp@intel.com> [missing core_param()]
[zohar@linux.ibm.com: included linux/module.h]
Tested-by: Chester Lin <clin@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Merge tag 'integrity-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"Continuing IMA policy rule cleanup and validation in particular for
measuring keys, adding/removing/updating informational and error
messages (e.g. "ima_appraise" boot command line option), and other bug
fixes (e.g. minimal data size validation before use, return code and
NULL pointer checking)"
* tag 'integrity-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: Fix NULL pointer dereference in ima_file_hash
evm: Check size of security.evm before using it
ima: Remove semicolon at the end of ima_get_binary_runtime_size()
ima: Don't ignore errors from crypto_shash_update()
ima: Use kmemdup rather than kmalloc+memcpy
integrity: include keyring name for unknown key request
ima: limit secure boot feedback scope for appraise
integrity: invalid kernel parameters feedback
ima: add check for enforced appraise option
integrity: Use current_uid() in integrity_audit_message()
ima: Fail rule parsing when asymmetric key measurement isn't supportable
ima: Pre-parse the list of keyrings in a KEY_CHECK rule
To perform partial reads, callers of kernel_read_file*() must have a
non-NULL file_size argument and a preallocated buffer. The new "offset"
argument can then be used to seek to specific locations in the file to
fill the buffer to, at most, "buf_size" per call.
Where possible, the LSM hooks can report whether a full file has been
read or not so that the contents can be reasoned about.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201002173828.2099543-14-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the kernel_read_file LSM hook is called with contents=false, IMA
can appraise the file directly, without requiring a filled buffer. When
such a buffer is available, though, IMA can continue to use it instead
of forcing a double read here.
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/lkml/20200706232309.12010-10-scott.branden@broadcom.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-13-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As with the kernel_load_data LSM hook, add a "contents" flag to the
kernel_read_file LSM hook that indicates whether the LSM can expect
a matching call to the kernel_post_read_file LSM hook with the full
contents of the file. With the coming addition of partial file read
support for kernel_read_file*() API, the LSM will no longer be able
to always see the entire contents of a file during the read calls.
For cases where the LSM must read examine the complete file contents,
it will need to do so on its own every time the kernel_read_file
hook is called with contents=false (or reject such cases). Adjust all
existing LSMs to retain existing behavior.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that security_post_load_data() is wired up, use it instead
of the NULL file argument style of security_post_read_file(),
and update the security_kernel_load_data() call to indicate that a
security_kernel_post_load_data() call is expected.
Wire up the IMA check to match earlier logic. Perhaps a generalized
change to ima_post_load_data() might look something like this:
return process_buffer_measurement(buf, size,
kernel_load_data_id_str(load_id),
read_idmap[load_id] ?: FILE_CHECK,
0, NULL);
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-10-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a few places in the kernel where LSMs would like to have
visibility into the contents of a kernel buffer that has been loaded or
read. While security_kernel_post_read_file() (which includes the
buffer) exists as a pairing for security_kernel_read_file(), no such
hook exists to pair with security_kernel_load_data().
Earlier proposals for just using security_kernel_post_read_file() with a
NULL file argument were rejected (i.e. "file" should always be valid for
the security_..._file hooks, but it appears at least one case was
left in the kernel during earlier refactoring. (This will be fixed in
a subsequent patch.)
Since not all cases of security_kernel_load_data() can have a single
contiguous buffer made available to the LSM hook (e.g. kexec image
segments are separately loaded), there needs to be a way for the LSM to
reason about its expectations of the hook coverage. In order to handle
this, add a "contents" argument to the "kernel_load_data" hook that
indicates if the newly added "kernel_post_load_data" hook will be called
with the full contents once loaded. That way, LSMs requiring full contents
can choose to unilaterally reject "kernel_load_data" with contents=false
(which is effectively the existing hook coverage), but when contents=true
they can allow it and later evaluate the "kernel_post_load_data" hook
once the buffer is loaded.
With this change, LSMs can gain coverage over non-file-backed data loads
(e.g. init_module(2) and firmware userspace helper), which will happen
in subsequent patches.
Additionally prepare IMA to start processing these cases.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for adding partial read support, add an optional output
argument to kernel_read_file*() that reports the file size so callers
can reason more easily about their reading progress.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-8-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for further refactoring of kernel_read_file*(), rename
the "max_size" argument to the more accurate "buf_size", and correct
its type to size_t. Add kerndoc to explain the specifics of how the
arguments will be used. Note that with buf_size now size_t, it can no
longer be negative (and was never called with a negative value). Adjust
callers to use it as a "maximum size" when *buf is NULL.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-7-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for refactoring kernel_read_file*(), remove the redundant
"size" argument which is not needed: it can be included in the return
code, with callers adjusted. (VFS reads already cannot be larger than
INT_MAX.)
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-6-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move kernel_read_file* out of linux/fs.h to its own linux/kernel_read_file.h
include file. That header gets pulled in just about everywhere
and doesn't really need functions not related to the general fs interface.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/r/20200706232309.12010-2-scott.branden@broadcom.com
Link: https://lore.kernel.org/r/20201002173828.2099543-4-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
FIRMWARE_PREALLOC_BUFFER is a "how", not a "what", and confuses the LSMs
that are interested in filtering between types of things. The "how"
should be an internal detail made uninteresting to the LSMs.
Fixes: a098ecd2fa ("firmware: support loading into a pre-allocated buffer")
Fixes: fd90bc559b ("ima: based on policy verify firmware signatures (pre-allocated buffer)")
Fixes: 4f0496d8ff ("ima: based on policy warn about loading firmware (pre-allocated buffer)")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201002173828.2099543-2-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ima_file_hash can be called when there is no iint->ima_hash available
even though the inode exists in the integrity cache. It is fairly
common for a file to not have a hash. (e.g. an mknodat, prior to the
file being closed).
Another example where this can happen (suggested by Jann Horn):
Process A does:
while(1) {
unlink("/tmp/imafoo");
fd = open("/tmp/imafoo", O_RDWR|O_CREAT|O_TRUNC, 0700);
if (fd == -1) {
perror("open");
continue;
}
write(fd, "A", 1);
close(fd);
}
and Process B does:
while (1) {
int fd = open("/tmp/imafoo", O_RDONLY);
if (fd == -1)
continue;
char *mapping = mmap(NULL, 0x1000, PROT_READ|PROT_EXEC,
MAP_PRIVATE, fd, 0);
if (mapping != MAP_FAILED)
munmap(mapping, 0x1000);
close(fd);
}
Due to the race to get the iint->mutex between ima_file_hash and
process_measurement iint->ima_hash could still be NULL.
Fixes: 6beea7afcc ("ima: add the ability to query the cached hash of a given file")
Signed-off-by: KP Singh <kpsingh@google.com>
Reviewed-by: Florent Revest <revest@chromium.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch removes the unnecessary semicolon at the end of
ima_get_binary_runtime_size().
Cc: stable@vger.kernel.org
Fixes: d158847ae8 ("ima: maintain memory size needed for serializing the measurement list")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Errors returned by crypto_shash_update() are not checked in
ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next
iteration of the loop. This patch adds a check after calling
crypto_shash_update() and returns immediately if the result is not zero.
Cc: stable@vger.kernel.org
Fixes: 3323eec921 ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Only emit an unknown/invalid message when setting the IMA appraise mode
to anything other than "enforce", when secureboot is enabled.
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
[zohar@linux.ibm.com: updated commit message]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The "enforce" string is allowed as an option for ima_appraise= kernel
paramenter per kernel-paramenters.txt and should be considered on the
parameter setup checking as a matter of completeness. Also it allows futher
checking on the options being passed by the user.
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measuring keys is currently only supported for asymmetric keys. In the
future, this might change.
For now, the "func=KEY_CHECK" and "keyrings=" options are only
appropriate when CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Make
this clear at policy load so that IMA policy authors don't assume that
these policy language constructs are supported.
Fixes: 2b60c0eced ("IMA: Read keyrings= option from the IMA policy")
Fixes: 5808611ccc ("IMA: Add KEY_CHECK func to measure keys")
Suggested-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The ima_keyrings buffer was used as a work buffer for strsep()-based
parsing of the "keyrings=" option of an IMA policy rule. This parsing
was re-performed each time an asymmetric key was added to a kernel
keyring for each loaded policy rule that contained a "keyrings=" option.
An example rule specifying this option is:
measure func=KEY_CHECK keyrings=a|b|c
The rule says to measure asymmetric keys added to any of the kernel
keyrings named "a", "b", or "c". The size of the buffer size was
equal to the size of the largest "keyrings=" value seen in a previously
loaded rule (5 + 1 for the NUL-terminator in the previous example) and
the buffer was pre-allocated at the time of policy load.
The pre-allocated buffer approach suffered from a couple bugs:
1) There was no locking around the use of the buffer so concurrent key
add operations, to two different keyrings, would result in the
strsep() loop of ima_match_keyring() to modify the buffer at the same
time. This resulted in unexpected results from ima_match_keyring()
and, therefore, could cause unintended keys to be measured or keys to
not be measured when IMA policy intended for them to be measured.
2) If the kstrdup() that initialized entry->keyrings in ima_parse_rule()
failed, the ima_keyrings buffer was freed and set to NULL even when a
valid KEY_CHECK rule was previously loaded. The next KEY_CHECK event
would trigger a call to strcpy() with a NULL destination pointer and
crash the kernel.
Remove the need for a pre-allocated global buffer by parsing the list of
keyrings in a KEY_CHECK rule at the time of policy load. The
ima_rule_entry will contain an array of string pointers which point to
the name of each keyring specified in the rule. No string processing
needs to happen at the time of asymmetric key add so iterating through
the list and doing a string comparison is all that's required at the
time of policy check.
In the process of changing how the "keyrings=" policy option is handled,
a couple additional bugs were fixed:
1) The rule parser accepted rules containing invalid "keyrings=" values
such as "a|b||c", "a|b|", or simply "|".
2) The /sys/kernel/security/ima/policy file did not display the entire
"keyrings=" value if the list of keyrings was longer than what could
fit in the fixed size tbuf buffer in ima_policy_show().
Fixes: 5c7bac9fb2 ("IMA: pre-allocate buffer to hold keyrings string")
Fixes: 2b60c0eced ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Merge tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
"A couple of minor documentation updates only for this release"
* tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
LSM: drop duplicated words in header file comments
Replace HTTP links with HTTPS ones: security
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
The IMA_APPRAISE_BOOTPARAM config allows enabling different "ima_appraise="
modes - log, fix, enforce - at run time, but not when IMA architecture
specific policies are enabled. This prevents properly labeling the
filesystem on systems where secure boot is supported, but not enabled on the
platform. Only when secure boot is actually enabled should these IMA
appraise modes be disabled.
This patch removes the compile time dependency and makes it a runtime
decision, based on the secure boot state of that platform.
Test results as follows:
-> x86-64 with secure boot enabled
[ 0.015637] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
[ 0.015668] ima: Secure boot enabled: ignoring ima_appraise=fix boot parameter option
-> powerpc with secure boot disabled
[ 0.000000] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
[ 0.000000] Secure boot mode disabled
-> Running the system without secure boot and with both options set:
CONFIG_IMA_APPRAISE_BOOTPARAM=y
CONFIG_IMA_ARCH_POLICY=y
Audit prompts "missing-hash" but still allow execution and, consequently,
filesystem labeling:
type=INTEGRITY_DATA msg=audit(07/09/2020 12:30:27.778:1691) : pid=4976
uid=root auid=root ses=2
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 op=appraise_data
cause=missing-hash comm=bash name=/usr/bin/evmctl dev="dm-0" ino=493150
res=no
Cc: stable@vger.kernel.org
Fixes: d958083a8f ("x86/ima: define arch_get_ima_policy() for x86")
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
AppArmor meets all the requirements for IMA in terms of audit rules
since commit e79c26d040 ("apparmor: Add support for audit rule
filtering"). Update IMA's Kconfig section for CONFIG_IMA_LSM_RULES to
reflect this.
Fixes: e79c26d040 ("apparmor: Add support for audit rule filtering")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Rename IMA's internal filter rule functions from security_filter_rule_*()
to ima_filter_rule_*(). This avoids polluting the security_* namespace,
which is typically reserved for general security subsystem
infrastructure.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Suggested-by: Casey Schaufler <casey@schaufler-ca.com>
[zohar@linux.ibm.com: reword using the term "filter", not "audit"]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLINE operation to
the rules in the IMA policy. This allows for some uniformity when
writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK,
and KEXEC_CMDLINE operations.
Prior to this patch, it was not possible to write a set of rules like
this:
dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t
dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t
dont_measure func=KEXEC_CMDLINE obj_type=foo_t
measure func=KEXEC_KERNEL_CHECK
measure func=KEXEC_INITRAMFS_CHECK
measure func=KEXEC_CMDLINE
The inode information associated with the kernel being loaded by a
kexec_kernel_load(2) syscall can now be included in the decision to
measure or not
Additonally, the uid, euid, and subj_* conditionals can also now be
used in KEXEC_CMDLINE rules. There was no technical reason as to why
those conditionals weren't being considered previously other than
ima_match_rules() didn't have a valid inode to use so it immediately
bailed out for KEXEC_CMDLINE operations rather than going through the
full list of conditional comparisons.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Make broader use of ima_rule_contains_lsm_cond() to check if a given
rule contains an LSM conditional. This is a code cleanup and has no
user-facing change.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Use ima_validate_rule(), at the end of the token parsing stage, to
verify combinations of actions, hooks, and flags. This is useful to
increase readability by consolidating such checks into a single function
and also because rule conditionals can be specified in arbitrary order
making it difficult to do comprehensive rule validation until the entire
rule has been parsed.
This allows for the check that ties together the "keyrings" conditional
with the KEY_CHECK function hook to be moved into the final rule
validation.
The modsig check no longer needs to compiled conditionally because the
token parser will ensure that modsig support is enabled before accepting
"imasig|modsig" appraise type values. The final rule validation will
ensure that appraise_type and appraise_flag options are only present in
appraise rules.
Finally, this allows for the check that ties together the "pcr"
conditional with the measure action to be moved into the final rule
validation.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Make args_p be of the char pointer type rather than have it be a void
pointer that gets casted to char pointer when it is used. It is a simple
NUL-terminated string as returned by match_strdup().
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The args_p member is a simple string that is allocated by
ima_rule_init(). Shallow copy it like other non-LSM references in
ima_rule_entry structs.
There are no longer any necessary error path cleanups to do in
ima_lsm_copy_rule().
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Verifying that a file hash is not blacklisted is currently only
supported for files with appended signatures (modsig). In the future,
this might change.
For now, the "appraise_flag" option is only appropriate for appraise
actions and its "blacklist" value is only appropriate when
CONFIG_IMA_APPRAISE_MODSIG is enabled and "appraise_flag=blacklist" is
only appropriate when "appraise_type=imasig|modsig" is also present.
Make this clear at policy load so that IMA policy authors don't assume
that other uses of "appraise_flag=blacklist" are supported.
Fixes: 273df864cf ("ima: Check against blacklisted hashes for files with modsig")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reivewed-by: Nayna Jain <nayna@linux.ibm.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The KEY_CHECK function only supports the uid, pcr, and keyrings
conditionals. Make this clear at policy load so that IMA policy authors
don't assume that other conditionals are supported.
Fixes: 5808611ccc ("IMA: Add KEY_CHECK func to measure keys")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The KEXEC_CMDLINE hook function only supports the pcr conditional. Make
this clear at policy load so that IMA policy authors don't assume that
other conditionals are supported.
Since KEXEC_CMDLINE's inception, ima_match_rules() has always returned
true on any loaded KEXEC_CMDLINE rule without any consideration for
other conditionals present in the rule. Make it clear that pcr is the
only supported KEXEC_CMDLINE conditional by returning an error during
policy load.
An example of why this is a problem can be explained with the following
rule:
dont_measure func=KEXEC_CMDLINE obj_type=foo_t
An IMA policy author would have assumed that rule is valid because the
parser accepted it but the result was that measurements for all
KEXEC_CMDLINE operations would be disabled.
Fixes: b0935123a1 ("IMA: Define a new hook to measure the kexec boot command line arguments")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Buffer based hook functions, such as KEXEC_CMDLINE and KEY_CHECK, can
only measure. The process_buffer_measurement() function quietly ignores
all actions except measure so make this behavior clear at the time of
policy load.
The parsing of the keyrings conditional had a check to ensure that it
was only specified with measure actions but the check should be on the
hook function and not the keyrings conditional since
"appraise func=KEY_CHECK" is not a valid rule.
Fixes: b0935123a1 ("IMA: Define a new hook to measure the kexec boot command line arguments")
Fixes: 5808611ccc ("IMA: Add KEY_CHECK func to measure keys")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry
members, such as .fsname and .keyrings, when an error is encountered
during rule parsing.
Set the args_p pointer to NULL after freeing it in the error path of
ima_lsm_rule_init() so that it isn't freed twice.
This fixes a memory leak seen when loading an rule that contains an
additional piece of allocated memory, such as an fsname, followed by an
invalid conditional:
# echo "measure fsname=tmpfs bad=cond" > /sys/kernel/security/ima/policy
-bash: echo: write error: Invalid argument
# echo scan > /sys/kernel/debug/kmemleak
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff98e7e4ece6c0 (size 8):
comm "bash", pid 672, jiffies 4294791843 (age 21.855s)
hex dump (first 8 bytes):
74 6d 70 66 73 00 6b a5 tmpfs.k.
backtrace:
[<00000000abab7413>] kstrdup+0x2e/0x60
[<00000000f11ede32>] ima_parse_add_rule+0x7d4/0x1020
[<00000000f883dd7a>] ima_write_policy+0xab/0x1d0
[<00000000b17cf753>] vfs_write+0xde/0x1d0
[<00000000b8ddfdea>] ksys_write+0x68/0xe0
[<00000000b8e21e87>] do_syscall_64+0x56/0xa0
[<0000000089ea7b98>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: f1b08bbcbd ("ima: define a new policy condition based on the filesystem name")
Fixes: 2b60c0eced ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Create a function, ima_free_rule(), to free all memory associated with
an ima_rule_entry. Use the new function to fix memory leaks of allocated
ima_rule_entry members, such as .fsname and .keyrings, when deleting a
list of rules.
Make the existing ima_lsm_free_rule() function specific to the LSM
audit rule array of an ima_rule_entry and require that callers make an
additional call to kfree to free the ima_rule_entry itself.
This fixes a memory leak seen when loading by a valid rule that contains
an additional piece of allocated memory, such as an fsname, followed by
an invalid rule that triggers a policy load failure:
# echo -e "dont_measure fsname=securityfs\nbad syntax" > \
/sys/kernel/security/ima/policy
-bash: echo: write error: Invalid argument
# echo scan > /sys/kernel/debug/kmemleak
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff9bab67ca12c0 (size 16):
comm "bash", pid 684, jiffies 4295212803 (age 252.344s)
hex dump (first 16 bytes):
73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5 securityfs.kkkk.
backtrace:
[<00000000adc80b1b>] kstrdup+0x2e/0x60
[<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020
[<00000000444825ac>] ima_write_policy+0xab/0x1d0
[<000000002b7f0d6c>] vfs_write+0xde/0x1d0
[<0000000096feedcf>] ksys_write+0x68/0xe0
[<0000000052b544a2>] do_syscall_64+0x56/0xa0
[<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: f1b08bbcbd ("ima: define a new policy condition based on the filesystem name")
Fixes: 2b60c0eced ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Ask the LSM to free its audit rule rather than directly calling kfree().
Both AppArmor and SELinux do additional work in their audit_rule_free()
hooks. Fix memory leaks by allowing the LSMs to perform necessary work.
Fixes: b169424551 ("ima: use the lsm policy update notifier")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Janne Karhunen <janne.karhunen@gmail.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Registers 8-9 are used to store measurements of the kernel and its
command line (e.g., grub2 bootloader with tpm module enabled). IMA
should include them in the boot aggregate. Registers 8-9 should be
only included in non-SHA1 digests to avoid ambiguity.
Signed-off-by: Maurizio Drocco <maurizio.drocco@ibm.com>
Reviewed-by: Bruno Meneguele <bmeneg@redhat.com>
Tested-by: Bruno Meneguele <bmeneg@redhat.com> (TPM 1.2, TPM 2.0)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Make sure IMA is enabled before checking mprotect change. Addresses
report of a 3.7% regression of boot-time.dhcp.
Fixes: 8eb613c0b8 ("ima: verify mprotect change is consistent with mmap policy")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Tested-by: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Commit 6cc7c266e5 ("ima: Call ima_calc_boot_aggregate() in
ima_eventdigest_init()") added a call to ima_calc_boot_aggregate() so that
the digest can be recalculated for the boot_aggregate measurement entry if
the 'd' template field has been requested. For the 'd' field, only SHA1 and
MD5 digests are accepted.
Given that ima_eventdigest_init() does not have the __init annotation, all
functions called should not have it. This patch removes __init from
ima_pcrread().
Cc: stable@vger.kernel.org
Fixes: 6cc7c266e5 ("ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init()")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'integrity-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"The main changes are extending the TPM 2.0 PCR banks with bank
specific file hashes, calculating the "boot_aggregate" based on other
TPM PCR banks, using the default IMA hash algorithm, instead of SHA1,
as the basis for the cache hash table key, and preventing the mprotect
syscall to circumvent an IMA mmap appraise policy rule.
- In preparation for extending TPM 2.0 PCR banks with bank specific
digests, commit 0b6cf6b97b ("tpm: pass an array of
tpm_extend_digest structures to tpm_pcr_extend()") modified
tpm_pcr_extend(). The original SHA1 file digests were
padded/truncated, before being extended into the other TPM PCR
banks. This pull request calculates and extends the TPM PCR banks
with bank specific file hashes completing the above change.
- The "boot_aggregate", the first IMA measurement list record, is the
"trusted boot" link between the pre-boot environment and the
running OS. With TPM 2.0, the "boot_aggregate" record is not
limited to being based on the SHA1 TPM PCR bank, but can be
calculated based on any enabled bank, assuming the hash algorithm
is also enabled in the kernel.
Other changes include the following and five other bug fixes/code
clean up:
- supporting both a SHA1 and a larger "boot_aggregate" digest in a
custom template format containing both the the SHA1 ('d') and
larger digests ('d-ng') fields.
- Initial hash table key fix, but additional changes would be good"
* tag 'integrity-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: Directly free *entry in ima_alloc_init_template() if digests is NULL
ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init()
ima: Directly assign the ima_default_policy pointer to ima_rules
ima: verify mprotect change is consistent with mmap policy
evm: Fix possible memory leak in evm_calc_hmac_or_hash()
ima: Set again build_ima_appraise variable
ima: Remove redundant policy rule set in add_rules()
ima: Fix ima digest hash table key calculation
ima: Use ima_hash_algo for collision detection in the measurement list
ima: Calculate and extend PCR with digests in ima_template_entry
ima: Allocate and initialize tfm for each PCR bank
ima: Switch to dynamically allocated buffer for template digests
ima: Store template digest directly in ima_template_entry
ima: Evaluate error in init_ima()
ima: Switch to ima_hash_algo for boot aggregate
To support multiple template digests, the static array entry->digest has
been replaced with a dynamically allocated array in commit aa724fe18a
("ima: Switch to dynamically allocated buffer for template digests"). The
array is allocated in ima_alloc_init_template() and if the returned pointer
is NULL, ima_free_template_entry() is called.
However, (*entry)->template_desc is not yet initialized while it is used by
ima_free_template_entry(). This patch fixes the issue by directly freeing
*entry without calling ima_free_template_entry().
Fixes: aa724fe18a ("ima: Switch to dynamically allocated buffer for template digests")
Reported-by: syzbot+223310b454ba6b75974e@syzkaller.appspotmail.com
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
If the template field 'd' is chosen and the digest to be added to the
measurement entry was not calculated with SHA1 or MD5, it is
recalculated with SHA1, by using the passed file descriptor. However, this
cannot be done for boot_aggregate, because there is no file descriptor.
This patch adds a call to ima_calc_boot_aggregate() in
ima_eventdigest_init(), so that the digest can be recalculated also for the
boot_aggregate entry.
Cc: stable@vger.kernel.org # 3.13.x
Fixes: 3ce1217d6c ("ima: define template fields library and new helpers")
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch prevents the following oops:
[ 10.771813] BUG: kernel NULL pointer dereference, address: 0000000000000
[...]
[ 10.779790] RIP: 0010:ima_match_policy+0xf7/0xb80
[...]
[ 10.798576] Call Trace:
[ 10.798993] ? ima_lsm_policy_change+0x2b0/0x2b0
[ 10.799753] ? inode_init_owner+0x1a0/0x1a0
[ 10.800484] ? _raw_spin_lock+0x7a/0xd0
[ 10.801592] ima_must_appraise.part.0+0xb6/0xf0
[ 10.802313] ? ima_fix_xattr.isra.0+0xd0/0xd0
[ 10.803167] ima_must_appraise+0x4f/0x70
[ 10.804004] ima_post_path_mknod+0x2e/0x80
[ 10.804800] do_mknodat+0x396/0x3c0
It occurs when there is a failure during IMA initialization, and
ima_init_policy() is not called. IMA hooks still call ima_match_policy()
but ima_rules is NULL. This patch prevents the crash by directly assigning
the ima_default_policy pointer to ima_rules when ima_rules is defined. This
wouldn't alter the existing behavior, as ima_rules is always set at the end
of ima_init_policy().
Cc: stable@vger.kernel.org # 3.7.x
Fixes: 07f6a79415 ("ima: add appraise action keywords and default rules")
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Files can be mmap'ed read/write and later changed to execute to circumvent
IMA's mmap appraise policy rules. Due to locking issues (mmap semaphore
would be taken prior to i_mutex), files can not be measured or appraised at
this point. Eliminate this integrity gap, by denying the mprotect
PROT_EXECUTE change, if an mmap appraise policy rule exists.
On mprotect change success, return 0. On failure, return -EACESS.
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
After adding the new add_rule() function in commit c52657d93b
("ima: refactor ima_init_policy()"), all appraisal flags are added to the
temp_ima_appraise variable. Revert to the previous behavior instead of
removing build_ima_appraise, to benefit from the protection offered by
__ro_after_init.
The mentioned commit introduced a bug, as it makes all the flags
modifiable, while build_ima_appraise flags can be protected with
__ro_after_init.
Cc: stable@vger.kernel.org # 5.0.x
Fixes: c52657d93b ("ima: refactor ima_init_policy()")
Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Function ima_appraise_flag() returns the flag to be set in
temp_ima_appraise depending on the hook identifier passed as an argument.
It is not necessary to set the flag again for the POLICY_CHECK hook.
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Function hash_long() accepts unsigned long, while currently only one byte
is passed from ima_hash_key(), which calculates a key for ima_htable.
Given that hashing the digest does not give clear benefits compared to
using the digest itself, remove hash_long() and return the modulus
calculated on the first two bytes of the digest with the number of slots.
Also reduce the depth of the hash table by doubling the number of slots.
Cc: stable@vger.kernel.org
Fixes: 3323eec921 ("integrity: IMA as an integrity service provider")
Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Acked-by: David.Laight@aculab.com (big endian system concerns)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch fixes the return value of ima_write_policy() when a new policy
is directly passed to IMA and the current policy requires appraisal of the
file containing the policy. Currently, if appraisal is not in ENFORCE mode,
ima_write_policy() returns 0 and leads user space applications to an
endless loop. Fix this issue by denying the operation regardless of the
appraisal mode.
Cc: stable@vger.kernel.org # 4.10.x
Fixes: 19f8a84713 ("ima: measure and appraise the IMA policy itself")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Commit a408e4a86b ("ima: open a new file instance if no read
permissions") tries to create a new file descriptor to calculate a file
digest if the file has not been opened with O_RDONLY flag. However, if a
new file descriptor cannot be obtained, it sets the FMODE_READ flag to
file->f_flags instead of file->f_mode.
This patch fixes this issue by replacing f_flags with f_mode as it was
before that commit.
Cc: stable@vger.kernel.org # 4.20.x
Fixes: a408e4a86b ("ima: open a new file instance if no read permissions")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Before calculating a digest for each PCR bank, collisions were detected
with a SHA1 digest. This patch includes ima_hash_algo among the algorithms
used to calculate the template digest and checks collisions on that digest.
The position in the measurement entry array of the template digest
calculated with the IMA default hash algorithm is stored in the
ima_hash_algo_idx global variable and is determined at IMA initialization
time.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch modifies ima_calc_field_array_hash() to calculate a template
digest for each allocated PCR bank and SHA1. It also passes the tpm_digest
array of the template entry to ima_pcr_extend() or in case of a violation,
the pre-initialized digests array filled with 0xff.
Padding with zeros is still done if the mapping between TPM algorithm ID
and crypto ID is unknown.
This patch calculates again the template digest when a measurement list is
restored. Copying only the SHA1 digest (due to the limitation of the
current measurement list format) is not sufficient, as hash collision
detection will be done on the digest calculated with the IMA default hash
algorithm.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch creates a crypto_shash structure for each allocated PCR bank and
for SHA1 if a bank with that algorithm is not currently allocated.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch dynamically allocates the array of tpm_digest structures in
ima_alloc_init_template() and ima_restore_template_data(). The size of the
array is equal to the number of PCR banks plus ima_extra_slots, to make
room for SHA1 and the IMA default hash algorithm, when PCR banks with those
algorithms are not allocated.
Calculating the SHA1 digest is mandatory, as SHA1 still remains the default
hash algorithm for the measurement list. When IMA will support the Crypto
Agile format, remaining digests will be also provided.
The position in the measurement entry array of the SHA1 digest is stored in
the ima_sha1_idx global variable and is determined at IMA initialization
time.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
In preparation for the patch that calculates a digest for each allocated
PCR bank, this patch passes to ima_calc_field_array_hash() the
ima_template_entry structure, so that digests can be directly stored in
that structure instead of ima_digest_data.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Evaluate error in init_ima() before register_blocking_lsm_notifier() and
return if not zero.
Cc: stable@vger.kernel.org # 5.3.x
Fixes: b169424551 ("ima: use the lsm policy update notifier")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
boot_aggregate is the first entry of IMA measurement list. Its purpose is
to link pre-boot measurements to IMA measurements. As IMA was designed to
work with a TPM 1.2, the SHA1 PCR bank was always selected even if a
TPM 2.0 with support for stronger hash algorithms is available.
This patch first tries to find a PCR bank with the IMA default hash
algorithm. If it does not find it, it selects the SHA256 PCR bank for
TPM 2.0 and SHA1 for TPM 1.2. Ultimately, it selects SHA1 also for TPM 2.0
if the SHA256 PCR bank is not found.
If none of the PCR banks above can be found, boot_aggregate file digest is
filled with zeros, as for TPM bypass, making it impossible to perform a
remote attestation of the system.
Cc: stable@vger.kernel.org # 5.1.x
Fixes: 879b589210 ("tpm: retrieve digest size of unknown algorithms with PCR read")
Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Every time a new architecture defines the IMA architecture specific
functions - arch_ima_get_secureboot() and arch_ima_get_policy(), the IMA
include file needs to be updated. To avoid this "noise", this patch
defines a new IMA Kconfig IMA_SECURE_AND_OR_TRUSTED_BOOT option, allowing
the different architectures to select it.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Philipp Rudo <prudo@linux.ibm.com> (s390)
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The #define for formatting log messages, pr_fmt, is duplicated in the
files under security/integrity.
This change moves the definition to security/integrity/integrity.h and
removes the duplicate definitions in the other files under
security/integrity.
With this change, the messages in the following files will be prefixed
with 'integrity'.
security/integrity/platform_certs/platform_keyring.c
security/integrity/platform_certs/load_powerpc.c
security/integrity/platform_certs/load_uefi.c
security/integrity/iint.c
e.g. "integrity: Error adding keys to platform keyring %s\n"
And the messages in the following file will be prefixed with 'ima'.
security/integrity/ima/ima_mok.c
e.g. "ima: Allocating IMA blacklist keyring.\n"
For the rest of the files under security/integrity, there will be no
change in the message format.
Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
process_buffer_measurement() does not have log messages for failure
conditions.
This change adds a log statement in the above function.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The kbuild Makefile specifies object files for vmlinux in the $(obj-y)
lists. These lists depend on the kernel configuration[1].
The kbuild Makefile for IMA combines the object files for IMA into a
single object file namely ima.o. All the object files for IMA should be
combined into ima.o. But certain object files are being added to their
own $(obj-y). This results in the log messages from those modules getting
prefixed with their respective base file name, instead of "ima". This is
inconsistent with the log messages from the IMA modules that are combined
into ima.o.
This change fixes the above issue.
[1] Documentation\kbuild\makefiles.rst
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
sm3 has been supported by the ima hash algorithm, but it is not
yet in the Kconfig configuration list. After adding, both ima and tpm2
can support sm3 well.
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull IMA updates from Mimi Zohar:
"Two new features - measuring certificates and querying IMA for a file
hash - and three bug fixes:
- Measuring certificates is like the rest of IMA, based on policy,
but requires loading a custom policy. Certificates loaded onto a
keyring, for example during early boot, before a custom policy has
been loaded, are queued and only processed after loading the custom
policy.
- IMA calculates and caches files hashes. Other kernel subsystems,
and possibly kernel modules, are interested in accessing these
cached file hashes.
The bug fixes prevent classifying a file short read (e.g. shutdown) as
an invalid file signature, add a missing blank when displaying the
securityfs policy rules containing LSM labels, and, lastly, fix the
handling of the IMA policy information for unknown LSM labels"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
IMA: Defined delayed workqueue to free the queued keys
IMA: Call workqueue functions to measure queued keys
IMA: Define workqueue for early boot key measurements
IMA: pre-allocate buffer to hold keyrings string
ima: ima/lsm policy rule loading logic bug fixes
ima: add the ability to query the cached hash of a given file
ima: Add a space after printing LSM rules for readability
IMA: fix measuring asymmetric keys Kconfig
IMA: Read keyrings= option from the IMA policy
IMA: Add support to limit measuring keys
KEYS: Call the IMA hook to measure keys
IMA: Define an IMA hook to measure keys
IMA: Add KEY_CHECK func to measure keys
IMA: Check IMA policy flag
ima: avoid appraise error for hash calc interrupt
Keys queued for measurement should be freed if a custom IMA policy
was not loaded. Otherwise, the keys will remain queued forever
consuming kernel memory.
This patch defines a delayed workqueue to handle the above scenario.
The workqueue handler is setup to execute 5 minutes after IMA
initialization is completed.
If a custom IMA policy is loaded before the workqueue handler is
scheduled to execute, the workqueue task is cancelled and any queued keys
are processed for measurement. But if a custom policy was not loaded then
the queued keys are just freed when the delayed workqueue handler is run.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reported-by: kernel test robot <rong.a.chen@intel.com> # sleeping
function called from invalid context
Reported-by: kbuild test robot <lkp@intel.com> # redefinition of
ima_init_key_queue() function.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measuring keys requires a custom IMA policy to be loaded. Keys should
be queued for measurement if a custom IMA policy is not yet loaded.
Keys queued for measurement, if any, should be processed when a custom
policy is loaded.
This patch updates the IMA hook function ima_post_key_create_or_update()
to queue the key if a custom IMA policy has not yet been loaded. And,
ima_update_policy() function, which is called when a custom IMA policy
is loaded, is updated to process queued keys.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measuring keys requires a custom IMA policy to be loaded. Keys created
or updated before a custom IMA policy is loaded should be queued and
will be processed after a custom policy is loaded.
This patch defines a workqueue for queuing keys when a custom IMA policy
has not yet been loaded. An intermediate Kconfig boolean option namely
IMA_QUEUE_EARLY_BOOT_KEYS is used to declare the workqueue functions.
A flag namely ima_process_keys is used to check if the key should be
queued or should be processed immediately.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
ima_match_keyring() is called while holding rcu read lock. Since this
function executes in atomic context, it should not call any function
that can sleep (such as kstrdup()).
This patch pre-allocates a buffer to hold the keyrings string read from
the IMA policy and uses that to match the given keyring.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Fixes: e9085e0ad3 ("IMA: Add support to limit measuring keys")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Keep the ima policy rules around from the beginning even if they appear
invalid at the time of loading, as they may become active after an lsm
policy load. However, loading a custom IMA policy with unknown LSM
labels is only safe after we have transitioned from the "built-in"
policy rules to a custom IMA policy.
Patch also fixes the rule re-use during the lsm policy reload and makes
some prints a bit more human readable.
Changelog:
v4:
- Do not allow the initial policy load refer to non-existing lsm rules.
v3:
- Fix too wide policy rule matching for non-initialized LSMs
v2:
- Fix log prints
Fixes: b169424551 ("ima: use the lsm policy update notifier")
Cc: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com>
Signed-off-by: Konsta Karsisto <konsta.karsisto@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This allows other parts of the kernel (perhaps a stacked LSM allowing
system monitoring, eg. the proposed KRSI LSM [1]) to retrieve the hash
of a given file from IMA if it's present in the iint cache.
It's true that the existence of the hash means that it's also in the
audit logs or in /sys/kernel/security/ima/ascii_runtime_measurements,
but it can be difficult to pull that information out for every
subsequent exec. This is especially true if a given host has been up
for a long time and the file was first measured a long time ago.
It should be kept in mind that this function gives access to cached
entries which can be removed, for instance on security_inode_free().
This is based on Peter Moody's patch:
https://sourceforge.net/p/linux-ima/mailman/message/33036180/
[1] https://lkml.org/lkml/2019/9/10/393
Signed-off-by: Florent Revest <revest@google.com>
Reviewed-by: KP Singh <kpsingh@chromium.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
When reading ima_policy from securityfs, there is a missing
space between output string of LSM rules and the remaining
rules.
Signed-off-by: Clay Chang <clayc@hpe.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
As a result of the asymmetric public keys subtype Kconfig option being
defined as tristate, with the existing IMA Makefile, ima_asymmetric_keys.c
could be built as a kernel module. To prevent this from happening, this
patch defines and uses an intermediate Kconfig boolean option named
IMA_MEASURE_ASYMMETRIC_KEYS.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: James.Bottomley <James.Bottomley@HansenPartnership.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reported-by: kbuild test robot <lkp@intel.com> # ima_asymmetric_keys.c
is built as a kernel module.
Fixes: 88e70da170 ("IMA: Define an IMA hook to measure keys")
Fixes: cb1aa3823c ("KEYS: Call the IMA hook to measure keys")
[zohar@linux.ibm.com: updated patch description]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Read "keyrings=" option, if specified in the IMA policy, and store in
the list of IMA rules when the configured IMA policy is read.
This patch defines a new policy token enum namely Opt_keyrings
and an option flag IMA_KEYRINGS for reading "keyrings=" option
from the IMA policy.
Updated ima_parse_rule() to parse "keyrings=" option in the policy.
Updated ima_policy_show() to display "keyrings=" option.
The following example illustrates how key measurement can be verified.
Sample "key" measurement rule in the IMA policy:
measure func=KEY_CHECK uid=0 keyrings=.ima|.evm template=ima-buf
Display "key" measurement in the IMA measurement list:
cat /sys/kernel/security/ima/ascii_runtime_measurements
10 faf3...e702 ima-buf sha256:27c915b8ddb9fae7214cf0a8a7043cc3eeeaa7539bcb136f8427067b5f6c3b7b .ima 308202863082...4aee
Verify "key" measurement data for a key added to ".ima" keyring:
cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements | grep -m 1 "\.ima" | cut -d' ' -f 6 | xxd -r -p |tee ima-cert.der | sha256sum | cut -d' ' -f 1
The output of the above command should match the template hash
of the first "key" measurement entry in the IMA measurement list for
the key added to ".ima" keyring.
The file namely "ima-cert.der" generated by the above command
should be a valid x509 certificate (in DER format) and should match
the one that was used to import the key to the ".ima" keyring.
The certificate file can be verified using openssl tool.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Limit measuring keys to those keys being loaded onto a given set of
keyrings only and when the user id (uid) matches if uid is specified
in the policy.
This patch defines a new IMA policy option namely "keyrings=" that
can be used to specify a set of keyrings. If this option is specified
in the policy for "measure func=KEY_CHECK" then only the keys
loaded onto a keyring given in the "keyrings=" option are measured.
If uid is specified in the policy then the key is measured only if
the current user id matches the one specified in the policy.
Added a new parameter namely "keyring" (name of the keyring) to
process_buffer_measurement(). The keyring name is passed to
ima_get_action() to determine the required action.
ima_match_rules() is updated to check keyring in the policy, if
specified, for KEY_CHECK function.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measure asymmetric keys used for verifying file signatures,
certificates, etc.
This patch defines a new IMA hook namely ima_post_key_create_or_update()
to measure the payload used to create a new asymmetric key or
update an existing asymmetric key.
Asymmetric key structure is defined only when
CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE is defined. Since the IMA hook
measures asymmetric keys, the IMA hook is defined in a new file namely
ima_asymmetric_keys.c which is built only if
CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE is defined.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measure keys loaded onto any keyring.
This patch defines a new IMA policy func namely KEY_CHECK to
measure keys. Updated ima_match_rules() to check for KEY_CHECK
and ima_parse_rule() to handle KEY_CHECK.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
process_buffer_measurement() may be called prior to IMA being
initialized (for instance, when the IMA hook is called when
a key is added to the .builtin_trusted_keys keyring), which
would result in a kernel panic.
This patch adds the check in process_buffer_measurement()
to return immediately if IMA is not initialized yet.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The integrity_kernel_read() call in ima_calc_file_hash_tfm() can return
a value of 0 before all bytes of the file are read. A value of 0 would
normally indicate an EOF. This has been observed if a user process is
causing a file appraisal and is terminated with a SIGTERM signal. The
most common occurrence of seeing the problem is if a shutdown or systemd
reload is initiated while files are being appraised.
The problem is similar to commit <f5e1040196db> (ima: always return
negative code for error) that fixed the problem in
ima_calc_file_hash_atfm().
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Patrick Callaghan <patrickc@linux.ibm.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().
This patch is generated using following script:
EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"
git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do
if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net
Asymmetric private keys are used to sign multiple files. The kernel
currently supports checking against blacklisted keys. However, if the
public key is blacklisted, any file signed by the blacklisted key will
automatically fail signature verification. Blacklisting the public key
is not fine enough granularity, as we might want to only blacklist a
particular file.
This patch adds support for checking against the blacklisted hash of
the file, without the appended signature, based on the IMA policy. It
defines a new policy option "appraise_flag=check_blacklist".
In addition to the blacklisted binary hashes stored in the firmware
"dbx" variable, the Linux kernel may be configured to load blacklisted
binary hashes onto the .blacklist keyring as well. The following
example shows how to blacklist a specific kernel module hash.
$ sha256sum kernel/kheaders.ko
77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
kernel/kheaders.ko
$ grep BLACKLIST .config
CONFIG_SYSTEM_BLACKLIST_KEYRING=y
CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list"
$ cat certs/blacklist-hash-list
"bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3"
Update the IMA custom measurement and appraisal policy
rules (/etc/ima-policy):
measure func=MODULE_CHECK template=ima-modsig
appraise func=MODULE_CHECK appraise_flag=check_blacklist
appraise_type=imasig|modsig
After building, installing, and rebooting the kernel:
545660333 ---lswrv 0 0 \_ blacklist:
bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
measure func=MODULE_CHECK template=ima-modsig
appraise func=MODULE_CHECK appraise_flag=check_blacklist
appraise_type=imasig|modsig
modprobe: ERROR: could not insert 'kheaders': Permission denied
10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig
sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40
2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko
10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig
sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40
2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko sha256:77fa889b3
5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648
016503040201300b06092a864886f70d01070131820264....
10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf
sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132
b blacklisted-hash
77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[zohar@linux.ibm.com: updated patch description]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com
process_buffer_measurement() is limited to measuring the kexec boot
command line. This patch makes process_buffer_measurement() more
generic, allowing it to measure other types of buffer data (e.g.
blacklisted binary hashes or key hashes).
process_buffer_measurement() may be called directly from an IMA hook
or as an auxiliary measurement record. In both cases the buffer
measurement is based on policy. This patch modifies the function to
conditionally retrieve the policy defined PCR and template for the IMA
hook case.
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[zohar@linux.ibm.com: added comment in process_buffer_measurement()]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-6-git-send-email-zohar@linux.ibm.com
Pull kernel lockdown mode from James Morris:
"This is the latest iteration of the kernel lockdown patchset, from
Matthew Garrett, David Howells and others.
From the original description:
This patchset introduces an optional kernel lockdown feature,
intended to strengthen the boundary between UID 0 and the kernel.
When enabled, various pieces of kernel functionality are restricted.
Applications that rely on low-level access to either hardware or the
kernel may cease working as a result - therefore this should not be
enabled without appropriate evaluation beforehand.
The majority of mainstream distributions have been carrying variants
of this patchset for many years now, so there's value in providing a
doesn't meet every distribution requirement, but gets us much closer
to not requiring external patches.
There are two major changes since this was last proposed for mainline:
- Separating lockdown from EFI secure boot. Background discussion is
covered here: https://lwn.net/Articles/751061/
- Implementation as an LSM, with a default stackable lockdown LSM
module. This allows the lockdown feature to be policy-driven,
rather than encoding an implicit policy within the mechanism.
The new locked_down LSM hook is provided to allow LSMs to make a
policy decision around whether kernel functionality that would allow
tampering with or examining the runtime state of the kernel should be
permitted.
The included lockdown LSM provides an implementation with a simple
policy intended for general purpose use. This policy provides a coarse
level of granularity, controllable via the kernel command line:
lockdown={integrity|confidentiality}
Enable the kernel lockdown feature. If set to integrity, kernel features
that allow userland to modify the running kernel are disabled. If set to
confidentiality, kernel features that allow userland to extract
confidential information from the kernel are also disabled.
This may also be controlled via /sys/kernel/security/lockdown and
overriden by kernel configuration.
New or existing LSMs may implement finer-grained controls of the
lockdown features. Refer to the lockdown_reason documentation in
include/linux/security.h for details.
The lockdown feature has had signficant design feedback and review
across many subsystems. This code has been in linux-next for some
weeks, with a few fixes applied along the way.
Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
when kernel lockdown is in confidentiality mode") is missing a
Signed-off-by from its author. Matthew responded that he is providing
this under category (c) of the DCO"
* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
kexec: Fix file verification on S390
security: constify some arrays in lockdown LSM
lockdown: Print current->comm in restriction messages
efi: Restrict efivar_ssdt_load when the kernel is locked down
tracefs: Restrict tracefs when the kernel is locked down
debugfs: Restrict debugfs when the kernel is locked down
kexec: Allow kexec_file() with appropriate IMA policy when locked down
lockdown: Lock down perf when in confidentiality mode
bpf: Restrict bpf when kernel lockdown is in confidentiality mode
lockdown: Lock down tracing and perf kprobes when in confidentiality mode
lockdown: Lock down /proc/kcore
x86/mmiotrace: Lock down the testmmiotrace module
lockdown: Lock down module params that specify hardware parameters (eg. ioport)
lockdown: Lock down TIOCSSERIAL
lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
acpi: Disable ACPI table override if the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
ACPI: Limit access to custom_method when the kernel is locked down
x86/msr: Restrict MSR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
...
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct ima_template_entry {
...
struct ima_field_data template_data[0]; /* template related data */
};
instance = kzalloc(sizeof(struct ima_template_entry) + count * sizeof(struct ima_field_data), GFP_NOFS);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_NOFS);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
If we can't parse the PKCS7 in the appended modsig, we will free the modsig
structure and then access one of its members to determine the error value.
Fixes: 39b0709636 ("ima: Implement support for module-style appended signatures")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Systems in lockdown mode should block the kexec of untrusted kernels.
For x86 and ARM we can ensure that a kernel is trustworthy by validating
a PE signature, but this isn't possible on other architectures. On those
platforms we can use IMA digital signatures instead. Add a function to
determine whether IMA has or will verify signatures for a given event type,
and if so permit kexec_file() even if the kernel is otherwise locked down.
This is restricted to cases where CONFIG_INTEGRITY_TRUSTED_KEYRING is set
in order to prevent an attacker from loading additional keys at runtime.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: linux-integrity@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
This is a preparatory patch for kexec_file_load() lockdown. A locked down
kernel needs to prevent unsigned kernel images from being loaded with
kexec_file_load(). Currently, the only way to force the signature
verification is compiling with KEXEC_VERIFY_SIG. This prevents loading
usigned images even when the kernel is not locked down at runtime.
This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE.
Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG
turns on the signature verification but allows unsigned images to be
loaded. KEXEC_SIG_FORCE disallows images without a valid signature.
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
cc: kexec@lists.infradead.org
Signed-off-by: James Morris <jmorris@namei.org>
integrity_kernel_read() can fail in which case we forward to call
ahash_request_free() on a currently running request. We have to wait
for its completion before we can free the request.
This was observed by interrupting a "find / -type f -xdev -print0 | xargs -0
cat 1>/dev/null" with ctrl-c on an IMA enabled filesystem.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
integrity_kernel_read() returns the number of bytes read. If this is
a short read then this positive value is returned from
ima_calc_file_hash_atfm(). Currently this is only indirectly called from
ima_calc_file_hash() and this function only tests for the return value
being zero or nonzero and also doesn't forward the return value.
Nevertheless there's no point in returning a positive value as an error,
so translate a short read into -EINVAL.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
If the IMA template contains the "modsig" or "d-modsig" field, then the
modsig should be added to the measurement list when the file is appraised.
And that is what normally happens, but if a measurement rule caused a file
containing a modsig to be measured before a different rule causes it to be
appraised, the resulting measurement entry will not contain the modsig
because it is only fetched during appraisal. When the appraisal rule
triggers, it won't store a new measurement containing the modsig because
the file was already measured.
We need to detect that situation and store an additional measurement with
the modsig. This is done by adding an IMA_MEASURE action flag if we read a
modsig and the IMA template contains a modsig field.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Define new "d-modsig" template field which holds the digest that is
expected to match the one contained in the modsig, and also new "modsig"
template field which holds the appended file signature.
Add a new "ima-modsig" defined template descriptor with the new fields as
well as the ones from the "ima-sig" descriptor.
Change ima_store_measurement() to accept a struct modsig * argument so that
it can be passed along to the templates via struct ima_event_data.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Obtain the modsig and calculate its corresponding hash in
ima_collect_measurement().
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Implement the appraise_type=imasig|modsig option, allowing IMA to read and
verify modsig signatures.
In case a file has both an xattr signature and an appended modsig, IMA will
only use the appended signature if the key used by the xattr signature
isn't present in the IMA or platform keyring.
Because modsig verification needs to convert from an integrity keyring id
to the keyring itself, add an integrity_keyring_from_id() function in
digsig.c so that integrity_modsig_verify() can use it.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Verify xattr signature in a separate function so that the logic in
ima_appraise_measurement() remains clear when it gains the ability to also
verify an appended module signature.
The code in the switch statement is unchanged except for having to
dereference the status and cause variables (since they're now pointers),
and fixing the style of a block comment to appease checkpatch.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Introduce the modsig keyword to the IMA policy syntax to specify that
a given hook should expect the file to have the IMA signature appended
to it. Here is how it can be used in a rule:
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
With this rule, IMA will accept either a signature stored in the extended
attribute or an appended signature.
For now, the rule above will behave exactly the same as if
appraise_type=imasig was specified. The actual modsig implementation
will be introduced separately.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
IMA policy rules are walked sequentially. Depending on the ordering of
the policy rules, the "template" field might be defined in one rule, but
will be replaced by subsequent, applicable rules, even if the rule does
not explicitly define the "template" field.
This patch initializes the "template" once and only replaces the
"template", when explicitly defined.
Fixes: 19453ce0bc ("IMA: support for per policy rule template formats")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull integrity updates from Mimi Zohar:
"Bug fixes, code clean up, and new features:
- IMA policy rules can be defined in terms of LSM labels, making the
IMA policy dependent on LSM policy label changes, in particular LSM
label deletions. The new environment, in which IMA-appraisal is
being used, frequently updates the LSM policy and permits LSM label
deletions.
- Prevent an mmap'ed shared file opened for write from also being
mmap'ed execute. In the long term, making this and other similar
changes at the VFS layer would be preferable.
- The IMA per policy rule template format support is needed for a
couple of new/proposed features (eg. kexec boot command line
measurement, appended signatures, and VFS provided file hashes).
- Other than the "boot-aggregate" record in the IMA measuremeent
list, all other measurements are of file data. Measuring and
storing the kexec boot command line in the IMA measurement list is
the first buffer based measurement included in the measurement
list"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
integrity: Introduce struct evm_xattr
ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition
KEXEC: Call ima_kexec_cmdline to measure the boot command line args
IMA: Define a new template field buf
IMA: Define a new hook to measure the kexec boot command line arguments
IMA: support for per policy rule template formats
integrity: Fix __integrity_init_keyring() section mismatch
ima: Use designated initializers for struct ima_event_data
ima: use the lsm policy update notifier
LSM: switch to blocking policy update notifiers
x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY
ima: Make arch_policy_entry static
ima: prevent a file already mmap'ed write to be mmap'ed execute
x86/ima: check EFI SetupMode too
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Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring ACL support from David Howells:
"This changes the permissions model used by keys and keyrings to be
based on an internal ACL by the following means:
- Replace the permissions mask internally with an ACL that contains a
list of ACEs, each with a specific subject with a permissions mask.
Potted default ACLs are available for new keys and keyrings.
ACE subjects can be macroised to indicate the UID and GID specified
on the key (which remain). Future commits will be able to add
additional subject types, such as specific UIDs or domain
tags/namespaces.
Also split a number of permissions to give finer control. Examples
include splitting the revocation permit from the change-attributes
permit, thereby allowing someone to be granted permission to revoke
a key without allowing them to change the owner; also the ability
to join a keyring is split from the ability to link to it, thereby
stopping a process accessing a keyring by joining it and thus
acquiring use of possessor permits.
- Provide a keyctl to allow the granting or denial of one or more
permits to a specific subject. Direct access to the ACL is not
granted, and the ACL cannot be viewed"
* tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
keys: Provide KEYCTL_GRANT_PERMISSION
keys: Replace uid/gid/perm permissions checking with an ACL
Even though struct evm_ima_xattr_data includes a fixed-size array to hold a
SHA1 digest, most of the code ignores the array and uses the struct to mean
"type indicator followed by data of unspecified size" and tracks the real
size of what the struct represents in a separate length variable.
The only exception to that is the EVM code, which correctly uses the
definition of struct evm_ima_xattr_data.
So make this explicit in the code by removing the length specification from
the array in struct evm_ima_xattr_data. Also, change the name of the
element from digest to data since in most places the array doesn't hold a
digest.
A separate struct evm_xattr is introduced, with the original definition of
evm_ima_xattr_data to be used in the places that actually expect that
definition, specifically the EVM HMAC code.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
MAX_TEMPLATE_NAME_LEN is used when restoring measurements carried over from
a kexec. It should be set to the length of a template containing all fields
except for 'd' and 'n', which don't need to be accounted for since they
shouldn't be defined in the same template description as 'd-ng' and 'n-ng'.
That length is greater than the current 15, so update using a sizeof() to
show where the number comes from and also can be visually shown to be
correct. The sizeof() is calculated at compile time.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
A buffer(kexec boot command line arguments) measured into IMA
measuremnt list cannot be appraised, without already being
aware of the buffer contents. Since hashes are non-reversible,
raw buffer is needed for validation or regenerating hash for
appraisal/attestation.
Add support to store/read the buffer contents in HEX.
The kexec cmdline hash is stored in the "d-ng" field of the
template data. It can be verified using
sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements |
grep kexec-cmdline | cut -d' ' -f 6 | xxd -r -p | sha256sum
- Add two new fields to ima_event_data to hold the buf and
buf_len
- Add a new template field 'buf' to be used to store/read
the buffer data.
- Updated process_buffer_meaurement to add the buffer to
ima_event_data. process_buffer_measurement added in
"Define a new IMA hook to measure the boot command line
arguments"
- Add a new template policy name ima-buf to represent
'd-ng|n-ng|buf'
Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split. This will also allow a
greater range of subjects to represented.
============
WHY DO THIS?
============
The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.
For SETATTR, this includes actions that are about controlling access to a
key:
(1) Changing a key's ownership.
(2) Changing a key's security information.
(3) Setting a keyring's restriction.
And actions that are about managing a key's lifetime:
(4) Setting an expiry time.
(5) Revoking a key.
and (proposed) managing a key as part of a cache:
(6) Invalidating a key.
Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.
Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission. It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.
As for SEARCH permission, that currently covers:
(1) Finding keys in a keyring tree during a search.
(2) Permitting keyrings to be joined.
(3) Invalidation.
But these don't really belong together either, since these actions really
need to be controlled separately.
Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.
===============
WHAT IS CHANGED
===============
The SETATTR permission is split to create two new permissions:
(1) SET_SECURITY - which allows the key's owner, group and ACL to be
changed and a restriction to be placed on a keyring.
(2) REVOKE - which allows a key to be revoked.
The SEARCH permission is split to create:
(1) SEARCH - which allows a keyring to be search and a key to be found.
(2) JOIN - which allows a keyring to be joined as a session keyring.
(3) INVAL - which allows a key to be invalidated.
The WRITE permission is also split to create:
(1) WRITE - which allows a key's content to be altered and links to be
added, removed and replaced in a keyring.
(2) CLEAR - which allows a keyring to be cleared completely. This is
split out to make it possible to give just this to an administrator.
(3) REVOKE - see above.
Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together. An ACE specifies a subject, such as:
(*) Possessor - permitted to anyone who 'possesses' a key
(*) Owner - permitted to the key owner
(*) Group - permitted to the key group
(*) Everyone - permitted to everyone
Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.
Further subjects may be made available by later patches.
The ACE also specifies a permissions mask. The set of permissions is now:
VIEW Can view the key metadata
READ Can read the key content
WRITE Can update/modify the key content
SEARCH Can find the key by searching/requesting
LINK Can make a link to the key
SET_SECURITY Can change owner, ACL, expiry
INVAL Can invalidate
REVOKE Can revoke
JOIN Can join this keyring
CLEAR Can clear this keyring
The KEYCTL_SETPERM function is then deprecated.
The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.
The KEYCTL_INVALIDATE function then requires INVAL.
The KEYCTL_REVOKE function then requires REVOKE.
The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.
The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.
======================
BACKWARD COMPATIBILITY
======================
To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.
It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.
SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned
on if a keyring is being altered.
The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.
It will make the following mappings:
(1) INVAL, JOIN -> SEARCH
(2) SET_SECURITY -> SETATTR
(3) REVOKE -> WRITE if SETATTR isn't already set
(4) CLEAR -> WRITE
Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.
=======
TESTING
=======
This passes the keyutils testsuite for all but a couple of tests:
(1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
if the type doesn't have ->read(). You still can't actually read the
key.
(2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
work as Other has been replaced with Everyone in the ACL.
Signed-off-by: David Howells <dhowells@redhat.com>
Currently during soft reboot(kexec_file_load) boot command line
arguments are not measured. Define hooks needed to measure kexec
command line arguments during soft reboot(kexec_file_load).
- A new ima hook ima_kexec_cmdline is defined to be called by the
kexec code.
- A new function process_buffer_measurement is defined to measure
the buffer hash into the IMA measurement list.
- A new func policy KEXEC_CMDLINE is defined to control the
measurement.
Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Admins may wish to log different measurements using different IMA
templates. Add support for overriding the default template on a per-rule
basis.
Inspired-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Designated initializers allow specifying only the members of the struct
that need initialization. Non-mentioned members are initialized to zero.
This makes the code a bit clearer (particularly in ima_add_boot_aggregate)
and also allows adding a new member to the struct without having to update
all struct initializations.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Don't do lazy policy updates while running the rule matching,
run the updates as they happen.
Depends on commit f242064c5df3 ("LSM: switch to blocking policy update notifiers")
Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
If enabled, ima arch specific policies always adds the measurements rules,
this makes it dependent on CONFIG_IMA. CONFIG_IMA_APPRAISE implicitly takes
care of this, however it is needed explicitly for CONFIG_KEXEC_VERIFY_SIG.
This patch adds the CONFIG_IMA dependency in combination with
CONFIG_KEXEC_VERIFY_SIG for CONFIG_IMA_ARCH_POLICY
Fixes: d958083a8f (x86/ima: define arch_get_ima_policy() for x86)
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Fix sparse warning:
security/integrity/ima/ima_policy.c:202:23: warning:
symbol 'arch_policy_entry' was not declared. Should it be static?
Fixes: 6191706246 ("ima: add support for arch specific policies")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: stable@vger.kernel.org (linux-5.0)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernel calls deny_write_access() to prevent a file already opened
for write from being executed and also prevents files being executed
from being opened for write. For some reason this does not extend to
files being mmap'ed execute.
From an IMA perspective, measuring/appraising the integrity of a file
being mmap'ed shared execute, without first making sure the file cannot
be modified, makes no sense. This patch prevents files, in policy,
already mmap'ed shared write, from being mmap'ed execute.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull integrity subsystem fixes from Mimi Zohar:
"Four bug fixes, none 5.2-specific, all marked for stable.
The first two are related to the architecture specific IMA policy
support. The other two patches, one is related to EVM signatures,
based on additional hash algorithms, and the other is related to
displaying the IMA policy"
* 'next-fixes-for-5.2-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: show rules with IMA_INMASK correctly
evm: check hash algorithm passed to init_desc()
ima: fix wrong signed policy requirement when not appraising
x86/ima: Check EFI_RUNTIME_SERVICES before using
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Show the '^' character when a policy rule has flag IMA_INMASK.
Fixes: 80eae209d6 ("IMA: allow reading back the current IMA policy")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kernel booted just with ima_policy=tcb (not with
ima_policy=appraise_tcb) shouldn't require signed policy.
Regression found with LTP test ima_policy.sh.
Fixes: c52657d93b ("ima: refactor ima_init_policy()")
Cc: stable@vger.kernel.org (linux-5.0)
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.
With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP. These would all need to be fixed if any shash algorithm
actually started sleeping. For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API. However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.
Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk. It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.
Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull tpm updates from James Morris:
- Clean up the transmission flow
Cleaned up the whole transmission flow. Locking of the chip is now
done in the level of tpm_try_get_ops() and tpm_put_ops() instead
taking the chip lock inside tpm_transmit(). The nested calls inside
tpm_transmit(), used with the resource manager, have been refactored
out.
Should make easier to perform more complex transactions with the TPM
without making the subsystem a bigger mess (e.g. encrypted channel
patches by James Bottomley).
- PPI 1.3 support
TPM PPI 1.3 introduces an additional optional command parameter that
may be needed for some commands. Display the parameter if the command
requires such a parameter. Only command 23 (SetPCRBanks) needs one.
The PPI request file will show output like this then:
# echo "23 16" > request
# cat request
23 16
# echo "5" > request
# cat request
5
- Extend all PCR banks in IMA
Instead of static PCR banks array, the array of available PCR banks
is now allocated dynamically. The digests sizes are determined
dynamically using a probe PCR read without relying crypto's static
list of hash algorithms.
This should finally make sealing of measurements in IMA safe and
secure.
- TPM 2.0 selftests
Added a test suite to tools/testing/selftests/tpm2 previously outside
of the kernel tree: https://github.com/jsakkine-intel/tpm2-scripts
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (37 commits)
tpm/ppi: Enable submission of optional command parameter for PPI 1.3
tpm/ppi: Possibly show command parameter if TPM PPI 1.3 is used
tpm/ppi: Display up to 101 operations as define for version 1.3
tpm/ppi: rename TPM_PPI_REVISION_ID to TPM_PPI_REVISION_ID_1
tpm/ppi: pass function revision ID to tpm_eval_dsm()
tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
KEYS: trusted: explicitly use tpm_chip structure from tpm_default_chip()
tpm: move tpm_chip definition to include/linux/tpm.h
tpm: retrieve digest size of unknown algorithms with PCR read
tpm: rename and export tpm2_digest and tpm2_algorithms
tpm: dynamically allocate the allocated_banks array
tpm: remove @flags from tpm_transmit()
tpm: take TPM chip power gating out of tpm_transmit()
tpm: introduce tpm_chip_start() and tpm_chip_stop()
tpm: remove TPM_TRANSMIT_UNLOCKED flag
tpm: use tpm_try_get_ops() in tpm-sysfs.c.
tpm: remove @space from tpm_transmit()
tpm: move TPM space code out of tpm_transmit()
tpm: move tpm_validate_commmand() to tpm2-space.c
tpm: clean up tpm_try_transmit() error handling flow
...
Pull integrity updates from James Morris:
"Mimi Zohar says:
'Linux 5.0 introduced the platform keyring to allow verifying the IMA
kexec kernel image signature using the pre-boot keys. This pull
request similarly makes keys on the platform keyring accessible for
verifying the PE kernel image signature.
Also included in this pull request is a new IMA hook that tags tmp
files, in policy, indicating the file hash needs to be calculated.
The remaining patches are cleanup'"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
evm: Use defined constant for UUID representation
ima: define ima_post_create_tmpfile() hook and add missing call
evm: remove set but not used variable 'xattr'
encrypted-keys: fix Opt_err/Opt_error = -1
kexec, KEYS: Make use of platform keyring for signature verify
integrity, KEYS: add a reference to platform keyring
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Merge tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
"A lucky 13 audit patches for v5.1.
Despite the rather large diffstat, most of the changes are from two
bug fix patches that move code from one Kconfig option to another.
Beyond that bit of churn, the remaining changes are largely cleanups
and bug-fixes as we slowly march towards container auditing. It isn't
all boring though, we do have a couple of new things: file
capabilities v3 support, and expanded support for filtering on
filesystems to solve problems with remote filesystems.
All changes pass the audit-testsuite. Please merge for v5.1"
* tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: mark expected switch fall-through
audit: hide auditsc_get_stamp and audit_serial prototypes
audit: join tty records to their syscall
audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL
audit: remove unused actx param from audit_rule_match
audit: ignore fcaps on umount
audit: clean up AUDITSYSCALL prototypes and stubs
audit: more filter PATH records keyed on filesystem magic
audit: add support for fcaps v3
audit: move loginuid and sessionid from CONFIG_AUDITSYSCALL to CONFIG_AUDIT
audit: add syscall information to CONFIG_CHANGE records
audit: hand taken context to audit_kill_trees for syscall logging
audit: give a clue what CONFIG_CHANGE op was involved
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warnings:
security/integrity/ima/ima_template_lib.c:85:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:940:18: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:943:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:972:21: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:974:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/smack/smack_lsm.c:3391:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/apparmor/domain.c:569:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
Warning level 3 was used: -Wimplicit-fallthrough=3
Also, add a missing break statement to fix the following warning:
security/integrity/ima/ima_appraise.c:116:26: warning: this statement may fall through [-Wimplicit-fallthrough=]
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Currently, tpm_pcr_extend() accepts as an input only a SHA1 digest.
This patch replaces the hash parameter of tpm_pcr_extend() with an array of
tpm_digest structures, so that the caller can provide a digest for each PCR
bank currently allocated in the TPM.
tpm_pcr_extend() will not extend banks for which no digest was provided,
as it happened before this patch, but instead it requires that callers
provide the full set of digests. Since the number of digests will always be
chip->nr_allocated_banks, the count parameter has been removed.
Due to the API change, ima_pcr_extend() and pcrlock() have been modified.
Since the number of allocated banks is not known in advance, the memory for
the digests must be dynamically allocated. To avoid performance degradation
and to avoid that a PCR extend is not done due to lack of memory, the array
of tpm_digest structures is allocated by the users of the TPM driver at
initialization time.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Mimi Zohar <zohar@linux.ibm.com> (on x86 for TPM 1.2 & PTT TPM 2.0)
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Currently, the TPM driver retrieves the digest size from a table mapping
TPM algorithms identifiers to identifiers defined by the crypto subsystem.
If the algorithm is not defined by the latter, the digest size can be
retrieved from the output of the PCR read command.
The patch modifies the definition of tpm_pcr_read() and tpm2_pcr_read() to
pass the desired hash algorithm and obtain the digest size at TPM startup.
Algorithms and corresponding digest sizes are stored in the new structure
tpm_bank_info, member of tpm_chip, so that the information can be used by
other kernel subsystems.
tpm_bank_info contains: the TPM algorithm identifier, necessary to generate
the event log as defined by Trusted Computing Group (TCG); the digest size,
to pad/truncate a digest calculated with a different algorithm; the crypto
subsystem identifier, to calculate the digest of event data.
This patch also protects against data corruption that could happen in the
bus, by checking that the digest size returned by the TPM during a PCR read
matches the size of the algorithm passed to tpm2_pcr_read().
For the initial PCR read, when digest sizes are not yet available, this
patch ensures that the amount of data copied from the output returned by
the TPM does not exceed the size of the array data are copied to.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
If tmpfiles can be made persistent, then newly created tmpfiles need to
be treated like any other new files in policy.
This patch indicates which newly created tmpfiles are in policy, causing
the file hash to be calculated on __fput().
Reported-by: Ignaz Forster <ignaz.forster@gmx.de>
[rgoldwyn@suse.com: Call ima_post_create_tmpfile() in vfs_tmpfile() as
opposed to do_tmpfile(). This will help the case for overlayfs where
copy_up is denied while overwriting a file.]
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The audit_rule_match() struct audit_context *actx parameter is not used
by any in-tree consumers (selinux, apparmour, integrity, smack).
The audit context is an internal audit structure that should only be
accessed by audit accessor functions.
It was part of commit 03d37d25e0 ("LSM/Audit: Introduce generic
Audit LSM hooks") but appears to have never been used.
Remove it.
Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/107
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the referenced commit title]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull TPM updates from James Morris:
- Support for partial reads of /dev/tpm0.
- Clean up for TPM 1.x code: move the commands to tpm1-cmd.c and make
everything to use the same data structure for building TPM commands
i.e. struct tpm_buf.
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (25 commits)
tpm: add support for partial reads
tpm: tpm_ibmvtpm: fix kdoc warnings
tpm: fix kdoc for tpm2_flush_context_cmd()
tpm: tpm_try_transmit() refactor error flow.
tpm: use u32 instead of int for PCR index
tpm1: reimplement tpm1_continue_selftest() using tpm_buf
tpm1: reimplement SAVESTATE using tpm_buf
tpm1: rename tpm1_pcr_read_dev to tpm1_pcr_read()
tpm1: implement tpm1_pcr_read_dev() using tpm_buf structure
tpm: tpm1: rewrite tpm1_get_random() using tpm_buf structure
tpm: tpm-space.c remove unneeded semicolon
tpm: tpm-interface.c drop unused macros
tpm: add tpm_auto_startup() into tpm-interface.c
tpm: factor out tpm_startup function
tpm: factor out tpm 1.x pm suspend flow into tpm1-cmd.c
tpm: move tpm 1.x selftest code from tpm-interface.c tpm1-cmd.c
tpm: factor out tpm1_get_random into tpm1-cmd.c
tpm: move tpm_getcap to tpm1-cmd.c
tpm: move tpm1_pcr_extend to tpm1-cmd.c
tpm: factor out tpm_get_timeouts()
...
Pull integrity updates from James Morris:
"In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load syscall.
Different signature verification methods exist for verifying the
kexec'ed kernel image. This adds additional support in IMA to prevent
loading unsigned kernel images via the kexec_load syscall,
independently of the IMA policy rules, based on the runtime "secure
boot" flag. An initial IMA kselftest is included.
In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.
(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here)"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
integrity: Remove references to module keyring
ima: Use inode_is_open_for_write
ima: Support platform keyring for kernel appraisal
efi: Allow the "db" UEFI variable to be suppressed
efi: Import certificates from UEFI Secure Boot
efi: Add an EFI signature blob parser
efi: Add EFI signature data types
integrity: Load certs to the platform keyring
integrity: Define a trusted platform keyring
selftests/ima: kexec_load syscall test
ima: don't measure/appraise files on efivarfs
x86/ima: retry detecting secure boot mode
docs: Extend trusted keys documentation for TPM 2.0
x86/ima: define arch_get_ima_policy() for x86
ima: add support for arch specific policies
ima: refactor ima_init_policy()
ima: prevent kexec_load syscall based on runtime secureboot flag
x86/ima: define arch_ima_get_secureboot
integrity: support new struct public_key_signature encoding field
totalram_pages and totalhigh_pages are made static inline function.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull general security subsystem updates from James Morris:
"The main changes here are Paul Gortmaker's removal of unneccesary
module.h infrastructure"
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
security: integrity: partial revert of make ima_main explicitly non-modular
security: fs: make inode explicitly non-modular
security: audit and remove any unnecessary uses of module.h
security: integrity: make evm_main explicitly non-modular
keys: remove needless modular infrastructure from ecryptfs_format
security: integrity: make ima_main explicitly non-modular
tomoyo: fix small typo
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Merge tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
"In the finest of holiday of traditions, I have a number of gifts to
share today. While most of them are re-gifts from others, unlike the
typical re-gift, these are things you will want in and around your
tree; I promise.
This pull request is perhaps a bit larger than our typical PR, but
most of it comes from Jan's rework of audit's fanotify code; a very
welcome improvement. We ran this through our normal regression tests,
as well as some newly created stress tests and everything looks good.
Richard added a few patches, mostly cleaning up a few things and and
shortening some of the audit records that we send to userspace; a
change the userspace folks are quite happy about.
Finally YueHaibing and I kick in a few patches to simplify things a
bit and make the code less prone to errors.
Lastly, I want to say thanks one more time to everyone who has
contributed patches, testing, and code reviews for the audit subsystem
over the past year. The project is what it is due to your help and
contributions - thank you"
* tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: (22 commits)
audit: remove duplicated include from audit.c
audit: shorten PATH cap values when zero
audit: use current whenever possible
audit: minimize our use of audit_log_format()
audit: remove WATCH and TREE config options
audit: use session_info helper
audit: localize audit_log_session_info prototype
audit: Use 'mark' name for fsnotify_mark variables
audit: Replace chunk attached to mark instead of replacing mark
audit: Simplify locking around untag_chunk()
audit: Drop all unused chunk nodes during deletion
audit: Guarantee forward progress of chunk untagging
audit: Allocate fsnotify mark independently of chunk
audit: Provide helper for dropping mark's chunk reference
audit: Remove pointless check in insert_hash()
audit: Factor out chunk replacement code
audit: Make hash table insertion safe against concurrent lookups
audit: Embed key into chunk
audit: Fix possible tagging failures
audit: Fix possible spurious -ENOSPC error
...
In commit 4f83d5ea64 ("security: integrity: make ima_main explicitly
non-modular") I'd removed <linux/module.h> after assuming that the
function is_module_sig_enforced() was an LSM function and not a core
kernel module function.
Unfortunately the typical .config selections used in build testing
provide an implicit <linux/module.h> presence, and so normal/typical
build testing did not immediately reveal my incorrect assumption.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-ima-devel@lists.sourceforge.net
Cc: linux-security-module@vger.kernel.org
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Start the policy_tokens and the associated enumeration from zero,
simplifying the pt macro.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'tpmdd-next-20181217' of git://git.infradead.org/users/jjs/linux-tpmdd into next-tpm
tpmdd updates for Linux v4.21
From Jarkko:
v4.21 updates:
* Support for partial reads of /dev/tpm0.
* Clean up for TPM 1.x code: move the commands to tpm1-cmd.c and make
everything to use the same data structure for building TPM commands
i.e. struct tpm_buf.
From Mimi:
In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load
syscall. Different signature verification methods exist for verifying
the kexec'ed kernel image. This pull request adds additional support
in IMA to prevent loading unsigned kernel images via the kexec_load
syscall, independently of the IMA policy rules, based on the runtime
"secure boot" flag. An initial IMA kselftest is included.
In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.
(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here.)
Use the aptly named function rather than open coding the check. No
functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
On secure boot enabled systems, the bootloader verifies the kernel
image and possibly the initramfs signatures based on a set of keys. A
soft reboot(kexec) of the system, with the same kernel image and
initramfs, requires access to the original keys to verify the
signatures.
This patch allows IMA-appraisal access to those original keys, now
loaded on the platform keyring, needed for verifying the kernel image
and initramfs signatures.
[zohar@linux.ibm.com: only use platform keyring if it's enabled (Thiago)]
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.
The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.
Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace as needed.
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
The Makefile/Kconfig entry controlling compilation of this code is:
obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
ima_policy.o ima_template.o ima_template_lib.o
security/integrity/ima/Kconfig:config IMA
security/integrity/ima/Kconfig- bool "Integrity Measurement Architecture(IMA)"
...meaning that it currently is not being built as a module by anyone.
Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.
We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-ima-devel@lists.sourceforge.net
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Update the builtin IMA policies specified on the boot command line
(eg. ima_policy="tcb|appraise_tcb") to permit accessing efivar files.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
On x86, there are two methods of verifying a kexec'ed kernel image
signature being loaded via the kexec_file_load syscall - an architecture
specific implementaton or a IMA KEXEC_KERNEL_CHECK appraisal rule. Neither
of these methods verify the kexec'ed kernel image signature being loaded
via the kexec_load syscall.
Secure boot enabled systems require kexec images to be signed. Therefore,
this patch loads an IMA KEXEC_KERNEL_CHECK policy rule on secure boot
enabled systems not configured with CONFIG_KEXEC_VERIFY_SIG enabled.
When IMA_APPRAISE_BOOTPARAM is configured, different IMA appraise modes
(eg. fix, log) can be specified on the boot command line, allowing unsigned
or invalidly signed kernel images to be kexec'ed. This patch permits
enabling IMA_APPRAISE_BOOTPARAM or IMA_ARCH_POLICY, but not both.
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Builtin IMA policies can be enabled on the boot command line, and replaced
with a custom policy, normally during early boot in the initramfs. Build
time IMA policy rules were recently added. These rules are automatically
enabled on boot and persist after loading a custom policy.
There is a need for yet another type of policy, an architecture specific
policy, which is derived at runtime during kernel boot, based on the
runtime secure boot flags. Like the build time policy rules, these rules
persist after loading a custom policy.
This patch adds support for loading an architecture specific IMA policy.
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Co-Developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch removes the code duplication in ima_init_policy() by defining
a new function named add_rules(). The new function adds the rules to the
initial IMA policy, the custom policy or both based on the policy mask
(IMA_DEFAULT_POLICY, IMA_CUSTOM_POLICY).
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
When CONFIG_KEXEC_VERIFY_SIG is enabled, the kexec_file_load syscall
requires the kexec'd kernel image to be signed. Distros are concerned
about totally disabling the kexec_load syscall. As a compromise, the
kexec_load syscall will only be disabled when CONFIG_KEXEC_VERIFY_SIG
is configured and the system is booted with secureboot enabled.
This patch disables the kexec_load syscall only for systems booted with
secureboot enabled.
[zohar@linux.ibm.com: add missing mesage on kexec_load failure]
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
There are many places, notably audit_log_task_info() and
audit_log_exit(), that take task_struct pointers but in reality they
are always working on the current task. This patch eliminates the
task_struct arguments and uses current directly which allows a number
of cleanups as well.
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The TPM specs defines PCR index as a positive number, and there is
no reason to use a signed number. It is also a possible security
issue as currently no functions check for a negative index,
which may become a large number when converted to u32.
Adjust the API to use u32 instead of int in all PCR related
functions.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Open a new file instance as opposed to changing file->f_mode when
the file is not readable. This is done to accomodate overlayfs
stacked file operations change. The real struct file is hidden
behind the overlays struct file. So, any file->f_mode manipulations are
not reflected on the real struct file. Open the file again in read mode
if original file cannot be read, read and calculate the hash.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: stable@vger.kernel.org (linux-4.19)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The 12 character temporary buffer is not necessarily long enough to hold
a 'long' value. Increase it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Constify some static data that is never modified,
so that it is placed in .rodata.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull integrity updates from James Morris:
"This adds support for EVM signatures based on larger digests, contains
a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the
IMA policy rules from the IMA-audit messages, addresses two deadlocks
due to either loading or searching for crypto algorithms, and cleans
up the audit messages"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
EVM: fix return value check in evm_write_xattrs()
integrity: prevent deadlock during digsig verification.
evm: Allow non-SHA1 digital signatures
evm: Don't deadlock if a crypto algorithm is unavailable
integrity: silence warning when CONFIG_SECURITYFS is not enabled
ima: Differentiate auditing policy rules from "audit" actions
ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
ima: Use audit_log_format() rather than audit_log_string()
ima: Call audit_log_string() rather than logging it untrusted
Pull TPM updates from James Morris:
- Migrate away from PM runtime as explicit cmdReady/goIdle transactions
for every command is a spec requirement. PM runtime adds only a layer
of complexity on our case.
- tpm_tis drivers can now specify the hwrng quality.
- TPM 2.0 code uses now tpm_buf for constructing messages. Jarkko
thinks Tomas Winkler has done the same for TPM 1.2, and will start
digging those changes from the patchwork in the near future.
- Bug fixes and clean ups
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
tpm: Implement tpm_default_chip() to find a TPM chip
tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
tpm: Allow tpm_tis drivers to set hwrng quality.
tpm: Return the actual size when receiving an unsupported command
tpm: separate cmd_ready/go_idle from runtime_pm
tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
tpm_tis_spi: Pass the SPI IRQ down to the driver
tpm: migrate tpm2_get_random() to use struct tpm_buf
tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
tpm: migrate tpm2_probe() to use struct tpm_buf
tpm: migrate tpm2_shutdown() to use struct tpm_buf
Pull security subsystem updates from James Morris:
- kstrdup() return value fix from Eric Biggers
- Add new security_load_data hook to differentiate security checking of
kernel-loaded binaries in the case of there being no associated file
descriptor, from Mimi Zohar.
- Add ability to IMA to specify a policy at build-time, rather than
just via command line params or by loading a custom policy, from
Mimi.
- Allow IMA and LSMs to prevent sysfs firmware load fallback (e.g. if
using signed firmware), from Mimi.
- Allow IMA to deny loading of kexec kernel images, as they cannot be
measured by IMA, from Mimi.
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
security: check for kstrdup() failure in lsm_append()
security: export security_kernel_load_data function
ima: based on policy warn about loading firmware (pre-allocated buffer)
module: replace the existing LSM hook in init_module
ima: add build time policy
ima: based on policy require signed firmware (sysfs fallback)
firmware: add call to LSM hook before firmware sysfs fallback
ima: based on policy require signed kexec kernel images
kexec: add call to LSM hook in original kexec_load syscall
security: define new LSM hook named security_kernel_load_data
MAINTAINERS: remove the outdated "LINUX SECURITY MODULE (LSM) FRAMEWORK" entry
Get rid of ima_used_chip and use ima_tpm_chip variable instead for
determining whether to use the TPM chip.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Rather than accessing the TPM functions by passing a NULL pointer for
the tpm_chip, which causes a lookup for a suitable chip every time, get a
hold of a tpm_chip and access the TPM functions using it.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action. This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.
Since we defined a new message type we can now also pass the
audit_context and get an associated SYSCALL record. This now produces
the following records when parsing IMA policy's rules:
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
func=MMAP_CHECK mask=MAY_EXEC res=1
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
func=FILE_CHECK mask=MAY_READ res=1
type=SYSCALL msg=audit(1527888965.738:320): arch=c000003e syscall=1 \
success=yes exit=17 a0=1 a1=55bcfcca9030 a2=11 a3=7fcc1b55fb38 \
items=0 ppid=1567 pid=1601 auid=0 uid=0 gid=0 euid=0 suid=0 \
fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="echo" \
exe="/usr/bin/echo" \
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
If Integrity is not auditing, IMA shouldn't audit, either.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Remove the usage of audit_log_string() and replace it with
audit_log_format().
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Suggested-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
The parameters passed to this logging function are all provided by
a privileged user and therefore we can call audit_log_string()
rather than audit_log_untrustedstring().
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Suggested-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Some systems are memory constrained but they need to load very large
firmwares. The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver. This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.
To resolve this problem, commit a098ecd2fa ("firmware: support loading
into a pre-allocated buffer") introduced request_firmware_into_buf() API
that allows drivers to request firmware be loaded directly into a
pre-allocated buffer.
Do devices using pre-allocated memory run the risk of the firmware being
accessible to the device prior to the completion of IMA's signature
verification any more than when using two buffers? (Refer to mailing list
discussion[1]).
Only on systems with an IOMMU can the access be prevented. As long as
the signature verification completes prior to the DMA map is performed,
the device can not access the buffer. This implies that the same buffer
can not be re-used. Can we ensure the buffer has not been DMA mapped
before using the pre-allocated buffer?
[1] https://lkml.org/lkml/2018/7/10/56
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
Both the init_module and finit_module syscalls call either directly
or indirectly the security_kernel_read_file LSM hook. This patch
replaces the direct call in init_module with a call to the new
security_kernel_load_data hook and makes the corresponding changes
in SELinux, LoadPin, and IMA.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
IMA by default does not measure, appraise or audit files, but can be
enabled at runtime by specifying a builtin policy on the boot command line
or by loading a custom policy.
This patch defines a build time policy, which verifies kernel modules,
firmware, kexec image, and/or the IMA policy signatures. This build time
policy is automatically enabled at runtime and persists after loading a
custom policy.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
With an IMA policy requiring signed firmware, this patch prevents
the sysfs fallback method of loading firmware.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
The original kexec_load syscall can not verify file signatures, nor can
the kexec image be measured. Based on policy, deny the kexec_load
syscall.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
just check ->f_mode in ima_appraise_measurement()
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
