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858 Commits

Author SHA1 Message Date
Linus Torvalds
726eb70e0d Char/Misc driver patches for 5.10-rc1
Here is the big set of char, misc, and other assorted driver subsystem
 patches for 5.10-rc1.
 
 There's a lot of different things in here, all over the drivers/
 directory.  Some summaries:
 	- soundwire driver updates
 	- habanalabs driver updates
 	- extcon driver updates
 	- nitro_enclaves new driver
 	- fsl-mc driver and core updates
 	- mhi core and bus updates
 	- nvmem driver updates
 	- eeprom driver updates
 	- binder driver updates and fixes
 	- vbox minor bugfixes
 	- fsi driver updates
 	- w1 driver updates
 	- coresight driver updates
 	- interconnect driver updates
 	- misc driver updates
 	- other minor driver updates
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char, misc, and other assorted driver subsystem
  patches for 5.10-rc1.

  There's a lot of different things in here, all over the drivers/
  directory. Some summaries:

   - soundwire driver updates

   - habanalabs driver updates

   - extcon driver updates

   - nitro_enclaves new driver

   - fsl-mc driver and core updates

   - mhi core and bus updates

   - nvmem driver updates

   - eeprom driver updates

   - binder driver updates and fixes

   - vbox minor bugfixes

   - fsi driver updates

   - w1 driver updates

   - coresight driver updates

   - interconnect driver updates

   - misc driver updates

   - other minor driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (396 commits)
  binder: fix UAF when releasing todo list
  docs: w1: w1_therm: Fix broken xref, mistakes, clarify text
  misc: Kconfig: fix a HISI_HIKEY_USB dependency
  LSM: Fix type of id parameter in kernel_post_load_data prototype
  misc: Kconfig: add a new dependency for HISI_HIKEY_USB
  firmware_loader: fix a kernel-doc markup
  w1: w1_therm: make w1_poll_completion static
  binder: simplify the return expression of binder_mmap
  test_firmware: Test partial read support
  firmware: Add request_partial_firmware_into_buf()
  firmware: Store opt_flags in fw_priv
  fs/kernel_file_read: Add "offset" arg for partial reads
  IMA: Add support for file reads without contents
  LSM: Add "contents" flag to kernel_read_file hook
  module: Call security_kernel_post_load_data()
  firmware_loader: Use security_post_load_data()
  LSM: Introduce kernel_post_load_data() hook
  fs/kernel_read_file: Add file_size output argument
  fs/kernel_read_file: Switch buffer size arg to size_t
  fs/kernel_read_file: Remove redundant size argument
  ...
2020-10-15 10:01:51 -07:00
Linus Torvalds
7b540812cc selinux/stable-5.10 PR 20201012
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Merge tag 'selinux-pr-20201012' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "A decent number of SELinux patches for v5.10, twenty two in total. The
  highlights are listed below, but all of the patches pass our test
  suite and merge cleanly.

   - A number of changes to how the SELinux policy is loaded and managed
     inside the kernel with the goal of improving the atomicity of a
     SELinux policy load operation.

     These changes account for the bulk of the diffstat as well as the
     patch count. A special thanks to everyone who contributed patches
     and fixes for this work.

   - Convert the SELinux policy read-write lock to RCU.

   - A tracepoint was added for audited SELinux access control events;
     this should help provide a more unified backtrace across kernel and
     userspace.

   - Allow the removal of security.selinux xattrs when a SELinux policy
     is not loaded.

   - Enable policy capabilities in SELinux policies created with the
     scripts/selinux/mdp tool.

   - Provide some "no sooner than" dates for the SELinux checkreqprot
     sysfs deprecation"

* tag 'selinux-pr-20201012' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (22 commits)
  selinux: provide a "no sooner than" date for the checkreqprot removal
  selinux: Add helper functions to get and set checkreqprot
  selinux: access policycaps with READ_ONCE/WRITE_ONCE
  selinux: simplify away security_policydb_len()
  selinux: move policy mutex to selinux_state, use in lockdep checks
  selinux: fix error handling bugs in security_load_policy()
  selinux: convert policy read-write lock to RCU
  selinux: delete repeated words in comments
  selinux: add basic filtering for audit trace events
  selinux: add tracepoint on audited events
  selinux: Create new booleans and class dirs out of tree
  selinux: Standardize string literal usage for selinuxfs directory names
  selinux: Refactor selinuxfs directory populating functions
  selinux: Create function for selinuxfs directory cleanup
  selinux: permit removing security.selinux xattr before policy load
  selinux: fix memdup.cocci warnings
  selinux: avoid dereferencing the policy prior to initialization
  selinux: fix allocation failure check on newpolicy->sidtab
  selinux: refactor changing booleans
  selinux: move policy commit after updating selinuxfs
  ...
2020-10-13 16:29:55 -07:00
Kees Cook
2039bda1fa LSM: Add "contents" flag to kernel_read_file hook
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>
2020-10-05 13:37:03 +02:00
Kees Cook
b64fcae74b LSM: Introduce kernel_post_load_data() hook
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>
2020-10-05 13:37:03 +02:00
Scott Branden
b89999d004 fs/kernel_read_file: Split into separate include file
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>
2020-10-05 13:34:18 +02:00
Lakshmi Ramasubramanian
8861d0af64 selinux: Add helper functions to get and set checkreqprot
checkreqprot data member in selinux_state struct is accessed directly by
SELinux functions to get and set. This could cause unexpected read or
write access to this data member due to compiler optimizations and/or
compiler's reordering of access to this field.

Add helper functions to get and set checkreqprot data member in
selinux_state struct. These helper functions use READ_ONCE and
WRITE_ONCE macros to ensure atomic read or write of memory for
this data member.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Suggested-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-09-15 14:36:28 -04:00
Stephen Smalley
9ff9abc4c6 selinux: move policy mutex to selinux_state, use in lockdep checks
Move the mutex used to synchronize policy changes (reloads and setting
of booleans) from selinux_fs_info to selinux_state and use it in
lockdep checks for rcu_dereference_protected() calls in the security
server functions.  This makes the dependency on the mutex explicit
in the code rather than relying on comments.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-27 09:52:47 -04:00
Stephen Smalley
1b8b31a2e6 selinux: convert policy read-write lock to RCU
Convert the policy read-write lock to RCU.  This is significantly
simplified by the earlier work to encapsulate the policy data
structures and refactor the policy load and boolean setting logic.
Move the latest_granting sequence number into the selinux_policy
structure so that it can be updated atomically with the policy.
Since removing the policy rwlock and moving latest_granting reduces
the selinux_ss structure to nothing more than a wrapper around the
selinux_policy pointer, get rid of the extra layer of indirection.

At present this change merely passes a hardcoded 1 to
rcu_dereference_check() in the cases where we know we do not need to
take rcu_read_lock(), with the preceding comment explaining why.
Alternatively we could pass fsi->mutex down from selinuxfs and
apply a lockdep check on it instead.

Based in part on earlier attempts to convert the policy rwlock
to RCU by Kaigai Kohei [1] and by Peter Enderborg [2].

[1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/
[2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-25 08:34:47 -04:00
Randy Dunlap
c76a2f9ecd selinux: delete repeated words in comments
Drop a repeated word in comments.
{open, is, then}

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: selinux@vger.kernel.org
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
[PM: fix subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-24 09:03:14 -04:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Stephen Smalley
9530a3e004 selinux: permit removing security.selinux xattr before policy load
Currently SELinux denies attempts to remove the security.selinux xattr
always, even when permissive or no policy is loaded.  This was originally
motivated by the view that all files should be labeled, even if that label
is unlabeled_t, and we shouldn't permit files that were once labeled to
have their labels removed entirely.  This however prevents removing
SELinux xattrs in the case where one "disables" SELinux by not loading
a policy (e.g. a system where runtime disable is removed and selinux=0
was not specified).  Allow removing the xattr before SELinux is
initialized.  We could conceivably permit it even after initialization
if permissive, or introduce a separate permission check here.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-20 21:55:31 -04:00
Jonathan Lebon
c8e222616c selinux: allow reading labels before policy is loaded
This patch does for `getxattr` what commit 3e3e24b420 ("selinux: allow
labeling before policy is loaded") did for `setxattr`; it allows
querying the current SELinux label on disk before the policy is loaded.

One of the motivations described in that commit message also drives this
patch: for Fedora CoreOS (and eventually RHEL CoreOS), we want to be
able to move the root filesystem for example, from xfs to ext4 on RAID,
on first boot, at initrd time.[1]

Because such an operation works at the filesystem level, we need to be
able to read the SELinux labels first from the original root, and apply
them to the files of the new root. The previous commit enabled the
second part of this process; this commit enables the first part.

[1] https://github.com/coreos/fedora-coreos-tracker/issues/94

Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Jonathan Lebon <jlebon@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-06-23 20:42:38 -04:00
Linus Torvalds
6c32978414 Notifications over pipes + Keyring notifications
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Merge tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull notification queue from David Howells:
 "This adds a general notification queue concept and adds an event
  source for keys/keyrings, such as linking and unlinking keys and
  changing their attributes.

  Thanks to Debarshi Ray, we do have a pull request to use this to fix a
  problem with gnome-online-accounts - as mentioned last time:

     https://gitlab.gnome.org/GNOME/gnome-online-accounts/merge_requests/47

  Without this, g-o-a has to constantly poll a keyring-based kerberos
  cache to find out if kinit has changed anything.

  [ There are other notification pending: mount/sb fsinfo notifications
    for libmount that Karel Zak and Ian Kent have been working on, and
    Christian Brauner would like to use them in lxc, but let's see how
    this one works first ]

  LSM hooks are included:

   - A set of hooks are provided that allow an LSM to rule on whether or
     not a watch may be set. Each of these hooks takes a different
     "watched object" parameter, so they're not really shareable. The
     LSM should use current's credentials. [Wanted by SELinux & Smack]

   - A hook is provided to allow an LSM to rule on whether or not a
     particular message may be posted to a particular queue. This is
     given the credentials from the event generator (which may be the
     system) and the watch setter. [Wanted by Smack]

  I've provided SELinux and Smack with implementations of some of these
  hooks.

  WHY
  ===

  Key/keyring notifications are desirable because if you have your
  kerberos tickets in a file/directory, your Gnome desktop will monitor
  that using something like fanotify and tell you if your credentials
  cache changes.

  However, we also have the ability to cache your kerberos tickets in
  the session, user or persistent keyring so that it isn't left around
  on disk across a reboot or logout. Keyrings, however, cannot currently
  be monitored asynchronously, so the desktop has to poll for it - not
  so good on a laptop. This facility will allow the desktop to avoid the
  need to poll.

  DESIGN DECISIONS
  ================

   - The notification queue is built on top of a standard pipe. Messages
     are effectively spliced in. The pipe is opened with a special flag:

        pipe2(fds, O_NOTIFICATION_PIPE);

     The special flag has the same value as O_EXCL (which doesn't seem
     like it will ever be applicable in this context)[?]. It is given up
     front to make it a lot easier to prohibit splice&co from accessing
     the pipe.

     [?] Should this be done some other way?  I'd rather not use up a new
         O_* flag if I can avoid it - should I add a pipe3() system call
         instead?

     The pipe is then configured::

        ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, queue_depth);
        ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter);

     Messages are then read out of the pipe using read().

   - It should be possible to allow write() to insert data into the
     notification pipes too, but this is currently disabled as the
     kernel has to be able to insert messages into the pipe *without*
     holding pipe->mutex and the code to make this work needs careful
     auditing.

   - sendfile(), splice() and vmsplice() are disabled on notification
     pipes because of the pipe->mutex issue and also because they
     sometimes want to revert what they just did - but one or more
     notification messages might've been interleaved in the ring.

   - The kernel inserts messages with the wait queue spinlock held. This
     means that pipe_read() and pipe_write() have to take the spinlock
     to update the queue pointers.

   - Records in the buffer are binary, typed and have a length so that
     they can be of varying size.

     This allows multiple heterogeneous sources to share a common
     buffer; there are 16 million types available, of which I've used
     just a few, so there is scope for others to be used. Tags may be
     specified when a watchpoint is created to help distinguish the
     sources.

   - Records are filterable as types have up to 256 subtypes that can be
     individually filtered. Other filtration is also available.

   - Notification pipes don't interfere with each other; each may be
     bound to a different set of watches. Any particular notification
     will be copied to all the queues that are currently watching for it
     - and only those that are watching for it.

   - When recording a notification, the kernel will not sleep, but will
     rather mark a queue as having lost a message if there's
     insufficient space. read() will fabricate a loss notification
     message at an appropriate point later.

   - The notification pipe is created and then watchpoints are attached
     to it, using one of:

        keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01);
        watch_mount(AT_FDCWD, "/", 0, fd, 0x02);
        watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x03);

     where in both cases, fd indicates the queue and the number after is
     a tag between 0 and 255.

   - Watches are removed if either the notification pipe is destroyed or
     the watched object is destroyed. In the latter case, a message will
     be generated indicating the enforced watch removal.

  Things I want to avoid:

   - Introducing features that make the core VFS dependent on the
     network stack or networking namespaces (ie. usage of netlink).

   - Dumping all this stuff into dmesg and having a daemon that sits
     there parsing the output and distributing it as this then puts the
     responsibility for security into userspace and makes handling
     namespaces tricky. Further, dmesg might not exist or might be
     inaccessible inside a container.

   - Letting users see events they shouldn't be able to see.

  TESTING AND MANPAGES
  ====================

   - The keyutils tree has a pipe-watch branch that has keyctl commands
     for making use of notifications. Proposed manual pages can also be
     found on this branch, though a couple of them really need to go to
     the main manpages repository instead.

     If the kernel supports the watching of keys, then running "make
     test" on that branch will cause the testing infrastructure to spawn
     a monitoring process on the side that monitors a notifications pipe
     for all the key/keyring changes induced by the tests and they'll
     all be checked off to make sure they happened.

        https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log/?h=pipe-watch

   - A test program is provided (samples/watch_queue/watch_test) that
     can be used to monitor for keyrings, mount and superblock events.
     Information on the notifications is simply logged to stdout"

* tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  smack: Implement the watch_key and post_notification hooks
  selinux: Implement the watch_key security hook
  keys: Make the KEY_NEED_* perms an enum rather than a mask
  pipe: Add notification lossage handling
  pipe: Allow buffers to be marked read-whole-or-error for notifications
  Add sample notification program
  watch_queue: Add a key/keyring notification facility
  security: Add hooks to rule on setting a watch
  pipe: Add general notification queue support
  pipe: Add O_NOTIFICATION_PIPE
  security: Add a hook for the point of notification insertion
  uapi: General notification queue definitions
2020-06-13 09:56:21 -07:00
Linus Torvalds
15a2bc4dbb Merge branch 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull execve updates from Eric Biederman:
 "Last cycle for the Nth time I ran into bugs and quality of
  implementation issues related to exec that could not be easily be
  fixed because of the way exec is implemented. So I have been digging
  into exec and cleanup up what I can.

  I don't think I have exec sorted out enough to fix the issues I
  started with but I have made some headway this cycle with 4 sets of
  changes.

   - promised cleanups after introducing exec_update_mutex

   - trivial cleanups for exec

   - control flow simplifications

   - remove the recomputation of bprm->cred

  The net result is code that is a bit easier to understand and work
  with and a decrease in the number of lines of code (if you don't count
  the added tests)"

* 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (24 commits)
  exec: Compute file based creds only once
  exec: Add a per bprm->file version of per_clear
  binfmt_elf_fdpic: fix execfd build regression
  selftests/exec: Add binfmt_script regression test
  exec: Remove recursion from search_binary_handler
  exec: Generic execfd support
  exec/binfmt_script: Don't modify bprm->buf and then return -ENOEXEC
  exec: Move the call of prepare_binprm into search_binary_handler
  exec: Allow load_misc_binary to call prepare_binprm unconditionally
  exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds
  exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds
  exec: Teach prepare_exec_creds how exec treats uids & gids
  exec: Set the point of no return sooner
  exec: Move handling of the point of no return to the top level
  exec: Run sync_mm_rss before taking exec_update_mutex
  exec: Fix spelling of search_binary_handler in a comment
  exec: Move the comment from above de_thread to above unshare_sighand
  exec: Rename flush_old_exec begin_new_exec
  exec: Move most of setup_new_exec into flush_old_exec
  exec: In setup_new_exec cache current in the local variable me
  ...
2020-06-04 14:07:08 -07:00
Eric W. Biederman
b8bff59926 exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds
Today security_bprm_set_creds has several implementations:
apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds,
smack_bprm_set_creds, and tomoyo_bprm_set_creds.

Except for cap_bprm_set_creds they all test bprm->called_set_creds and
return immediately if it is true.  The function cap_bprm_set_creds
ignores bprm->calld_sed_creds entirely.

Create a new LSM hook security_bprm_creds_for_exec that is called just
before prepare_binprm in __do_execve_file, resulting in a LSM hook
that is called exactly once for the entire of exec.  Modify the bits
of security_bprm_set_creds that only want to be called once per exec
into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds
behind.

Remove bprm->called_set_creds all of it's former users have been moved
to security_bprm_creds_for_exec.

Add or upate comments a appropriate to bring them up to date and
to reflect this change.

Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com> # For the LSM and Smack bits
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-20 14:45:31 -05:00
David Howells
3e412ccc22 selinux: Implement the watch_key security hook
Implement the watch_key security hook to make sure that a key grants the
caller View permission in order to set a watch on a key.

For the moment, the watch_devices security hook is left unimplemented as
it's not obvious what the object should be since the queue is global and
didn't previously exist.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
2020-05-19 15:47:15 +01:00
David Howells
8c0637e950 keys: Make the KEY_NEED_* perms an enum rather than a mask
Since the meaning of combining the KEY_NEED_* constants is undefined, make
it so that you can't do that by turning them into an enum.

The enum is also given some extra values to represent special
circumstances, such as:

 (1) The '0' value is reserved and causes a warning to trap the parameter
     being unset.

 (2) The key is to be unlinked and we require no permissions on it, only
     the keyring, (this replaces the KEY_LOOKUP_FOR_UNLINK flag).

 (3) An override due to CAP_SYS_ADMIN.

 (4) An override due to an instantiation token being present.

 (5) The permissions check is being deferred to later key_permission()
     calls.

The extra values give the opportunity for LSMs to audit these situations.

[Note: This really needs overhauling so that lookup_user_key() tells
 key_task_permission() and the LSM what operation is being done and leaves
 it to those functions to decide how to map that onto the available
 permits.  However, I don't really want to make these change in the middle
 of the notifications patchset.]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
cc: Paul Moore <paul@paul-moore.com>
cc: Stephen Smalley <stephen.smalley.work@gmail.com>
cc: Casey Schaufler <casey@schaufler-ca.com>
cc: keyrings@vger.kernel.org
cc: selinux@vger.kernel.org
2020-05-19 15:42:22 +01:00
Linus Torvalds
39e16d9342 selinux/stable-5.7 PR 20200430
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Merge tag 'selinux-pr-20200430' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux fixes from Paul Moore:
 "Two more SELinux patches to fix problems in the v5.7-rcX releases.

  Wei Yongjun's patch fixes a return code in an error path, and my patch
  fixes a problem where we were not correctly applying access controls
  to all of the netlink messages in the netlink_send LSM hook"

* tag 'selinux-pr-20200430' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: properly handle multiple messages in selinux_netlink_send()
  selinux: fix error return code in cond_read_list()
2020-04-30 16:35:45 -07:00
Paul Moore
fb73974172 selinux: properly handle multiple messages in selinux_netlink_send()
Fix the SELinux netlink_send hook to properly handle multiple netlink
messages in a single sk_buff; each message is parsed and subject to
SELinux access control.  Prior to this patch, SELinux only inspected
the first message in the sk_buff.

Cc: stable@vger.kernel.org
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-04-30 16:18:37 -04:00
Linus Torvalds
b3aa112d57 selinux/stable-5.7 PR 20200330
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Merge tag 'selinux-pr-20200330' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux updates from Paul Moore:
 "We've got twenty SELinux patches for the v5.7 merge window, the
  highlights are below:

   - Deprecate setting /sys/fs/selinux/checkreqprot to 1.

     This flag was originally created to deal with legacy userspace and
     the READ_IMPLIES_EXEC personality flag. We changed the default from
     1 to 0 back in Linux v4.4 and now we are taking the next step of
     deprecating it, at some point in the future we will take the final
     step of rejecting 1.

   - Allow kernfs symlinks to inherit the SELinux label of the parent
     directory. In order to preserve backwards compatibility this is
     protected by the genfs_seclabel_symlinks SELinux policy capability.

   - Optimize how we store filename transitions in the kernel, resulting
     in some significant improvements to policy load times.

   - Do a better job calculating our internal hash table sizes which
     resulted in additional policy load improvements and likely general
     SELinux performance improvements as well.

   - Remove the unused initial SIDs (labels) and improve how we handle
     initial SIDs.

   - Enable per-file labeling for the bpf filesystem.

   - Ensure that we properly label NFS v4.2 filesystems to avoid a
     temporary unlabeled condition.

   - Add some missing XFS quota command types to the SELinux quota
     access controls.

   - Fix a problem where we were not updating the seq_file position
     index correctly in selinuxfs.

   - We consolidate some duplicated code into helper functions.

   - A number of list to array conversions.

   - Update Stephen Smalley's email address in MAINTAINERS"

* tag 'selinux-pr-20200330' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: clean up indentation issue with assignment statement
  NFS: Ensure security label is set for root inode
  MAINTAINERS: Update my email address
  selinux: avtab_init() and cond_policydb_init() return void
  selinux: clean up error path in policydb_init()
  selinux: remove unused initial SIDs and improve handling
  selinux: reduce the use of hard-coded hash sizes
  selinux: Add xfs quota command types
  selinux: optimize storage of filename transitions
  selinux: factor out loop body from filename_trans_read()
  security: selinux: allow per-file labeling for bpffs
  selinux: generalize evaluate_cond_node()
  selinux: convert cond_expr to array
  selinux: convert cond_av_list to array
  selinux: convert cond_list to array
  selinux: sel_avc_get_stat_idx should increase position index
  selinux: allow kernfs symlinks to inherit parent directory context
  selinux: simplify evaluate_cond_node()
  Documentation,selinux: deprecate setting checkreqprot to 1
  selinux: move status variables out of selinux_ss
2020-03-31 15:07:55 -07:00
Richard Haines
e4cfa05e9b selinux: Add xfs quota command types
Add Q_XQUOTAOFF, Q_XQUOTAON and Q_XSETQLIM to trigger filesystem quotamod
permission check.

Add Q_XGETQUOTA, Q_XGETQSTAT, Q_XGETQSTATV and Q_XGETNEXTQUOTA to trigger
filesystem quotaget permission check.

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-22 14:41:21 -05:00
Connor O'Brien
4ca54d3d30 security: selinux: allow per-file labeling for bpffs
Add support for genfscon per-file labeling of bpffs files. This allows
for separate permissions for different pinned bpf objects, which may
be completely unrelated to each other.

Signed-off-by: Connor O'Brien <connoro@google.com>
Signed-off-by: Steven Moreland <smoreland@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-11 22:02:54 -05:00
Linus Torvalds
a5650acb5f selinux/stable-5.6 PR 20200210
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Merge tag 'selinux-pr-20200210' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux fixes from Paul Moore:
 "Two small fixes: one fixes a locking problem in the recently merged
  label translation code, the other fixes an embarrassing 'binderfs' /
  'binder' filesystem name check"

* tag 'selinux-pr-20200210' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: fix sidtab string cache locking
  selinux: fix typo in filesystem name
2020-02-10 16:51:35 -08:00
Christian Göttsche
7470d0d13f selinux: allow kernfs symlinks to inherit parent directory context
Currently symlinks on kernel filesystems, like sysfs, are labeled on
creation with the parent filesystem root sid.

Allow symlinks to inherit the parent directory context, so fine-grained
kernfs labeling can be applied to symlinks too and checking contexts
doesn't complain about them.

For backward-compatibility this behavior is contained in a new policy
capability: genfs_seclabel_symlinks

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-10 10:49:01 -05:00
Stephen Smalley
e9c38f9fc2 Documentation,selinux: deprecate setting checkreqprot to 1
Deprecate setting the SELinux checkreqprot tunable to 1 via kernel
parameter or /sys/fs/selinux/checkreqprot.  Setting it to 0 is left
intact for compatibility since Android and some Linux distributions
do so for security and treat an inability to set it as a fatal error.
Eventually setting it to 0 will become a no-op and the kernel will
stop using checkreqprot's value internally altogether.

checkreqprot was originally introduced as a compatibility mechanism
for legacy userspace and the READ_IMPLIES_EXEC personality flag.
However, if set to 1, it weakens security by allowing mappings to be
made executable without authorization by policy.  The default value
for the SECURITY_SELINUX_CHECKREQPROT_VALUE config option was changed
from 1 to 0 in commit 2a35d196c1 ("selinux: change
CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default") and both Android
and Linux distributions began explicitly setting
/sys/fs/selinux/checkreqprot to 0 some time ago.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-10 10:49:01 -05:00
Ondrej Mosnacek
4b36cb773a selinux: move status variables out of selinux_ss
It fits more naturally in selinux_state, since it reflects also global
state (the enforcing and policyload fields).

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-10 10:49:01 -05:00
Linus Torvalds
c9d35ee049 Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs file system parameter updates from Al Viro:
 "Saner fs_parser.c guts and data structures. The system-wide registry
  of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
  the horror switch() in fs_parse() that would have to grow another case
  every time something got added to that system-wide registry.

  New syntax types can be added by filesystems easily now, and their
  namespace is that of functions - not of system-wide enum members. IOW,
  they can be shared or kept private and if some turn out to be widely
  useful, we can make them common library helpers, etc., without having
  to do anything whatsoever to fs_parse() itself.

  And we already get that kind of requests - the thing that finally
  pushed me into doing that was "oh, and let's add one for timeouts -
  things like 15s or 2h". If some filesystem really wants that, let them
  do it. Without somebody having to play gatekeeper for the variants
  blessed by direct support in fs_parse(), TYVM.

  Quite a bit of boilerplate is gone. And IMO the data structures make a
  lot more sense now. -200LoC, while we are at it"

* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
  tmpfs: switch to use of invalfc()
  cgroup1: switch to use of errorfc() et.al.
  procfs: switch to use of invalfc()
  hugetlbfs: switch to use of invalfc()
  cramfs: switch to use of errofc() et.al.
  gfs2: switch to use of errorfc() et.al.
  fuse: switch to use errorfc() et.al.
  ceph: use errorfc() and friends instead of spelling the prefix out
  prefix-handling analogues of errorf() and friends
  turn fs_param_is_... into functions
  fs_parse: handle optional arguments sanely
  fs_parse: fold fs_parameter_desc/fs_parameter_spec
  fs_parser: remove fs_parameter_description name field
  add prefix to fs_context->log
  ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
  new primitive: __fs_parse()
  switch rbd and libceph to p_log-based primitives
  struct p_log, variants of warnf() et.al. taking that one instead
  teach logfc() to handle prefices, give it saner calling conventions
  get rid of cg_invalf()
  ...
2020-02-08 13:26:41 -08:00
Al Viro
d7167b1499 fs_parse: fold fs_parameter_desc/fs_parameter_spec
The former contains nothing but a pointer to an array of the latter...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:37 -05:00
Eric Sandeen
96cafb9ccb fs_parser: remove fs_parameter_description name field
Unused now.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:36 -05:00
Hridya Valsaraju
a20456aef8 selinux: fix typo in filesystem name
Correct the filesystem name to "binder" to enable genfscon per-file
labelling for binderfs.

Fixes: 7a4b519474 ("selinux: allow per-file labelling for binderfs")
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: slight style changes to the subj/description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-05 18:23:13 -05:00
Stephen Smalley
98aa00345d selinux: fix regression introduced by move_mount(2) syscall
commit 2db154b3ea ("vfs: syscall: Add move_mount(2) to move mounts around")
introduced a new move_mount(2) system call and a corresponding new LSM
security_move_mount hook but did not implement this hook for any existing
LSM.  This creates a regression for SELinux with respect to consistent
checking of mounts; the existing selinux_mount hook checks mounton
permission to the mount point path.  Provide a SELinux hook
implementation for move_mount that applies this same check for
consistency.  In the future we may wish to add a new move_mount
filesystem permission and check as well, but this addresses
the immediate regression.

Fixes: 2db154b3ea ("vfs: syscall: Add move_mount(2) to move mounts around")
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-20 07:42:37 -05:00
Paul Moore
cb89e24658 selinux: remove redundant allocation and helper functions
This patch removes the inode, file, and superblock security blob
allocation functions and moves the associated code into the
respective LSM hooks.  This patch also removes the inode_doinit()
function as it was a trivial wrapper around
inode_doinit_with_dentry() and called from one location in the code.

Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-16 14:38:03 -05:00
Huaisheng Ye
df4779b5d2 selinux: remove redundant selinux_nlmsg_perm
selinux_nlmsg_perm is used for only by selinux_netlink_send. Remove
the redundant function to simplify the code.

Fix a typo by suggestion from Stephen.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-16 14:34:36 -05:00
Ondrej Mosnacek
cfff75d897 selinux: reorder hooks to make runtime disable less broken
Commit b1d9e6b064 ("LSM: Switch to lists of hooks") switched the LSM
infrastructure to use per-hook lists, which meant that removing the
hooks for a given module was no longer atomic. Even though the commit
clearly documents that modules implementing runtime revmoval of hooks
(only SELinux attempts this madness) need to take special precautions to
avoid race conditions, SELinux has never addressed this.

By inserting an artificial delay between the loop iterations of
security_delete_hooks() (I used 100 ms), booting to a state where
SELinux is enabled, but policy is not yet loaded, and running these
commands:

    while true; do ping -c 1 <some IP>; done &
    echo -n 1 >/sys/fs/selinux/disable
    kill %1
    wait

...I was able to trigger NULL pointer dereferences in various places. I
also have a report of someone getting panics on a stock RHEL-8 kernel
after setting SELINUX=disabled in /etc/selinux/config and rebooting
(without adding "selinux=0" to kernel command-line).

Reordering the SELinux hooks such that those that allocate structures
are removed last seems to prevent these panics. It is very much possible
that this doesn't make the runtime disable completely race-free, but at
least it makes the operation much less fragile.

Cc: stable@vger.kernel.org
Fixes: b1d9e6b064 ("LSM: Switch to lists of hooks")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-10 15:26:55 -05:00
Ondrej Mosnacek
65cddd5098 selinux: treat atomic flags more carefully
The disabled/enforcing/initialized flags are all accessed concurrently
by threads so use the appropriate accessors that ensure atomicity and
document that it is expected.

Use smp_load/acquire...() helpers (with memory barriers) for the
initialized flag, since it gates access to the rest of the state
structures.

Note that the disabled flag is currently not used for anything other
than avoiding double disable, but it will be used for bailing out of
hooks once security_delete_hooks() is removed.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-10 15:19:39 -05:00
Stephen Smalley
b78b7d59bd selinux: make default_noexec read-only after init
SELinux checks whether VM_EXEC is set in the VM_DATA_DEFAULT_FLAGS
during initialization and saves the result in default_noexec for use
in its mmap and mprotect hook function implementations to decide
whether to apply EXECMEM, EXECHEAP, EXECSTACK, and EXECMOD checks.
Mark default_noexec as ro_after_init to prevent later clearing it
and thereby disabling these checks.  It is only set legitimately from
init code.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-10 12:26:20 -05:00
Huaisheng Ye
b82f3f6894 selinux: remove redundant msg_msg_alloc_security
selinux_msg_msg_alloc_security only calls msg_msg_alloc_security but
do nothing else. And also msg_msg_alloc_security is just used by the
former.

Remove the redundant function to simplify the code.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-10 11:32:13 -05:00
Hridya Valsaraju
7a4b519474 selinux: allow per-file labelling for binderfs
This patch allows genfscon per-file labeling for binderfs.
This is required to have separate permissions to allow
access to binder, hwbinder and vndbinder devices which are
relocating to binderfs.

Acked-by: Jeff Vander Stoep <jeffv@google.com>
Acked-by: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-06 21:11:18 -05:00
Stephen Smalley
6c5a682e64 selinux: clean up selinux_enabled/disabled/enforcing_boot
Rename selinux_enabled to selinux_enabled_boot to make it clear that
it only reflects whether SELinux was enabled at boot.  Replace the
references to it in the MAC_STATUS audit log in sel_write_enforce()
with hardcoded "1" values because this code is only reachable if SELinux
is enabled and does not change its value, and update the corresponding
MAC_STATUS audit log in sel_write_disable().  Stop clearing
selinux_enabled in selinux_disable() since it is not used outside of
initialization code that runs before selinux_disable() can be reached.
Mark both selinux_enabled_boot and selinux_enforcing_boot as __initdata
since they are only used in initialization code.

Wrap the disabled field in the struct selinux_state with
CONFIG_SECURITY_SELINUX_DISABLE since it is only used for
runtime disable.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-18 21:22:46 -05:00
Yang Guo
210a292874 selinux: remove unnecessary selinux cred request
task_security_struct was obtained at the beginning of may_create
and selinux_inode_init_security, no need to obtain again.
may_create will be called very frequently when create dir and file.

Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Yang Guo <guoyang2@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-12 08:50:39 -05:00
Stephen Smalley
5298d0b9b9 selinux: clean up selinux_inode_permission MAY_NOT_BLOCK tests
Through a somewhat convoluted series of changes, we have ended up
with multiple unnecessary occurrences of (flags & MAY_NOT_BLOCK)
tests in selinux_inode_permission().  Clean it up and simplify.
No functional change.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09 18:47:27 -05:00
Stephen Smalley
0188d5c025 selinux: fall back to ref-walk if audit is required
commit bda0be7ad9 ("security: make inode_follow_link RCU-walk aware")
passed down the rcu flag to the SELinux AVC, but failed to adjust the
test in slow_avc_audit() to also return -ECHILD on LSM_AUDIT_DATA_DENTRY.
Previously, we only returned -ECHILD if generating an audit record with
LSM_AUDIT_DATA_INODE since this was only relevant from inode_permission.
Move the handling of MAY_NOT_BLOCK to avc_audit() and its inlined
equivalent in selinux_inode_permission() immediately after we determine
that audit is required, and always fall back to ref-walk in this case.

Fixes: bda0be7ad9 ("security: make inode_follow_link RCU-walk aware")
Reported-by: Will Deacon <will@kernel.org>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09 18:37:47 -05:00
Stephen Smalley
1a37079c23 selinux: revert "stop passing MAY_NOT_BLOCK to the AVC upon follow_link"
This reverts commit e46e01eebb ("selinux: stop passing MAY_NOT_BLOCK
to the AVC upon follow_link"). The correct fix is to instead fall
back to ref-walk if audit is required irrespective of the specific
audit data type.  This is done in the next commit.

Fixes: e46e01eebb ("selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link")
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09 18:28:56 -05:00
Stephen Smalley
59438b4647 security,lockdown,selinux: implement SELinux lockdown
Implement a SELinux hook for lockdown.  If the lockdown module is also
enabled, then a denial by the lockdown module will take precedence over
SELinux, so SELinux can only further restrict lockdown decisions.
The SELinux hook only distinguishes at the granularity of integrity
versus confidentiality similar to the lockdown module, but includes the
full lockdown reason as part of the audit record as a hint in diagnosing
what triggered the denial.  To support this auditing, move the
lockdown_reasons[] string array from being private to the lockdown
module to the security framework so that it can be used by the lsm audit
code and so that it is always available even when the lockdown module
is disabled.

Note that the SELinux implementation allows the integrity and
confidentiality reasons to be controlled independently from one another.
Thus, in an SELinux policy, one could allow operations that specify
an integrity reason while blocking operations that specify a
confidentiality reason. The SELinux hook implementation is
stricter than the lockdown module in validating the provided reason value.

Sample AVC audit output from denials:
avc:  denied  { integrity } for pid=3402 comm="fwupd"
 lockdown_reason="/dev/mem,kmem,port" scontext=system_u:system_r:fwupd_t:s0
 tcontext=system_u:system_r:fwupd_t:s0 tclass=lockdown permissive=0

avc:  denied  { confidentiality } for pid=4628 comm="cp"
 lockdown_reason="/proc/kcore access"
 scontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023
 tcontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023
 tclass=lockdown permissive=0

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
[PM: some merge fuzz do the the perf hooks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09 17:53:58 -05:00
Linus Torvalds
ceb3074745 y2038: syscall implementation cleanups
This is a series of cleanups for the y2038 work, mostly intended
 for namespace cleaning: the kernel defines the traditional
 time_t, timeval and timespec types that often lead to y2038-unsafe
 code. Even though the unsafe usage is mostly gone from the kernel,
 having the types and associated functions around means that we
 can still grow new users, and that we may be missing conversions
 to safe types that actually matter.
 
 There are still a number of driver specific patches needed to
 get the last users of these types removed, those have been
 submitted to the respective maintainers.
 
 Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 cleanups from Arnd Bergmann:
 "y2038 syscall implementation cleanups

  This is a series of cleanups for the y2038 work, mostly intended for
  namespace cleaning: the kernel defines the traditional time_t, timeval
  and timespec types that often lead to y2038-unsafe code. Even though
  the unsafe usage is mostly gone from the kernel, having the types and
  associated functions around means that we can still grow new users,
  and that we may be missing conversions to safe types that actually
  matter.

  There are still a number of driver specific patches needed to get the
  last users of these types removed, those have been submitted to the
  respective maintainers"

Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/

* tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits)
  y2038: alarm: fix half-second cut-off
  y2038: ipc: fix x32 ABI breakage
  y2038: fix typo in powerpc vdso "LOPART"
  y2038: allow disabling time32 system calls
  y2038: itimer: change implementation to timespec64
  y2038: move itimer reset into itimer.c
  y2038: use compat_{get,set}_itimer on alpha
  y2038: itimer: compat handling to itimer.c
  y2038: time: avoid timespec usage in settimeofday()
  y2038: timerfd: Use timespec64 internally
  y2038: elfcore: Use __kernel_old_timeval for process times
  y2038: make ns_to_compat_timeval use __kernel_old_timeval
  y2038: socket: use __kernel_old_timespec instead of timespec
  y2038: socket: remove timespec reference in timestamping
  y2038: syscalls: change remaining timeval to __kernel_old_timeval
  y2038: rusage: use __kernel_old_timeval
  y2038: uapi: change __kernel_time_t to __kernel_old_time_t
  y2038: stat: avoid 'time_t' in 'struct stat'
  y2038: ipc: remove __kernel_time_t reference from headers
  y2038: vdso: powerpc: avoid timespec references
  ...
2019-12-01 14:00:59 -08:00
Linus Torvalds
ba75082efc selinux/stable-5.5 PR 20191126
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Merge tag 'selinux-pr-20191126' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "Only three SELinux patches for v5.5:

   - Remove the size limit on SELinux policies, the limitation was a
     lingering vestige and no longer necessary.

   - Allow file labeling before the policy is loaded. This should ease
     some of the burden when the policy is initially loaded (no need to
     relabel files), but it should also help enable some new system
     concepts which dynamically create the root filesystem in the
     initrd.

   - Add support for the "greatest lower bound" policy construct which
     is defined as the intersection of the MLS range of two SELinux
     labels"

* tag 'selinux-pr-20191126' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: default_range glblub implementation
  selinux: allow labeling before policy is loaded
  selinux: remove load size limit
2019-11-30 16:55:37 -08:00
Linus Torvalds
8c39f71ee2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "This is mostly to fix the iwlwifi regression:

  1) Flush GRO state properly in iwlwifi driver, from Alexander Lobakin.

  2) Validate TIPC link name with properly length macro, from John
     Rutherford.

  3) Fix completion init and device query timeouts in ibmvnic, from
     Thomas Falcon.

  4) Fix SKB size calculation for netlink messages in psample, from
     Nikolay Aleksandrov.

  5) Similar kind of fix for OVS flow dumps, from Paolo Abeni.

  6) Handle queue allocation failure unwind properly in gve driver, we
     could try to release pages we didn't allocate. From Jeroen de
     Borst.

  7) Serialize TX queue SKB list accesses properly in mscc ocelot
     driver. From Yangbo Lu"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net:
  net: usb: aqc111: Use the correct style for SPDX License Identifier
  net: phy: Use the correct style for SPDX License Identifier
  net: wireless: intel: iwlwifi: fix GRO_NORMAL packet stalling
  net: mscc: ocelot: use skb queue instead of skbs list
  net: mscc: ocelot: avoid incorrect consuming in skbs list
  gve: Fix the queue page list allocated pages count
  net: inet_is_local_reserved_port() port arg should be unsigned short
  openvswitch: fix flow command message size
  net: phy: dp83869: Fix return paths to return proper values
  net: psample: fix skb_over_panic
  net: usbnet: Fix -Wcast-function-type
  net: hso: Fix -Wcast-function-type
  net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port)
  ibmvnic: Serialize device queries
  ibmvnic: Bound waits for device queries
  ibmvnic: Terminate waiting device threads after loss of service
  ibmvnic: Fix completion structure initialization
  net-sctp: replace some sock_net(sk) with just 'net'
  net: Fix a documentation bug wrt. ip_unprivileged_port_start
  tipc: fix link name length check
2019-11-27 17:17:40 -08:00
Maciej Żenczykowski
82f31ebf61 net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port)
Note that the sysctl write accessor functions guarantee that:
  net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0]
invariant is maintained, and as such the max() in selinux hooks is actually spurious.

ie. even though
  if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) {
per logic is the same as
  if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) {
it is actually functionally equivalent to:
  if (snum < low || snum > high) {
which is equivalent to:
  if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) {
even though the first clause is spurious.

But we want to hold on to it in case we ever want to change what what
inet_port_requires_bind_service() means (for example by changing
it from a, by default, [0..1024) range to some sort of set).

Test: builds, git 'grep inet_prot_sock' finds no other references
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 13:20:46 -08:00
Arnd Bergmann
ddbc7d0657 y2038: move itimer reset into itimer.c
Preparing for a change to the itimer internals, stop using the
do_setitimer() symbol and instead use a new higher-level interface.

The do_getitimer()/do_setitimer functions can now be made static,
allowing the compiler to potentially produce better object code.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15 14:38:30 +01:00
Joel Fernandes (Google)
da97e18458 perf_event: Add support for LSM and SELinux checks
In current mainline, the degree of access to perf_event_open(2) system
call depends on the perf_event_paranoid sysctl.  This has a number of
limitations:

1. The sysctl is only a single value. Many types of accesses are controlled
   based on the single value thus making the control very limited and
   coarse grained.
2. The sysctl is global, so if the sysctl is changed, then that means
   all processes get access to perf_event_open(2) opening the door to
   security issues.

This patch adds LSM and SELinux access checking which will be used in
Android to access perf_event_open(2) for the purposes of attaching BPF
programs to tracepoints, perf profiling and other operations from
userspace. These operations are intended for production systems.

5 new LSM hooks are added:
1. perf_event_open: This controls access during the perf_event_open(2)
   syscall itself. The hook is called from all the places that the
   perf_event_paranoid sysctl is checked to keep it consistent with the
   systctl. The hook gets passed a 'type' argument which controls CPU,
   kernel and tracepoint accesses (in this context, CPU, kernel and
   tracepoint have the same semantics as the perf_event_paranoid sysctl).
   Additionally, I added an 'open' type which is similar to
   perf_event_paranoid sysctl == 3 patch carried in Android and several other
   distros but was rejected in mainline [1] in 2016.

2. perf_event_alloc: This allocates a new security object for the event
   which stores the current SID within the event. It will be useful when
   the perf event's FD is passed through IPC to another process which may
   try to read the FD. Appropriate security checks will limit access.

3. perf_event_free: Called when the event is closed.

4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event.

5. perf_event_write: Called from the ioctl(2) syscalls for the event.

[1] https://lwn.net/Articles/696240/

Since Peter had suggest LSM hooks in 2016 [1], I am adding his
Suggested-by tag below.

To use this patch, we set the perf_event_paranoid sysctl to -1 and then
apply selinux checking as appropriate (default deny everything, and then
add policy rules to give access to domains that need it). In the future
we can remove the perf_event_paranoid sysctl altogether.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: James Morris <jmorris@namei.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: rostedt@goodmis.org
Cc: Yonghong Song <yhs@fb.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: jeffv@google.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: primiano@google.com
Cc: Song Liu <songliubraving@fb.com>
Cc: rsavitski@google.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Matthew Garrett <matthewgarrett@google.com>
Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
2019-10-17 21:31:55 +02:00