Commit Graph

508 Commits

Author SHA1 Message Date
David Howells
d80a8f1b58 vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
When NFS superblocks are created by automounting, their LSM parameters
aren't set in the fs_context struct prior to sget_fc() being called,
leading to failure to match existing superblocks.

This bug leads to messages like the following appearing in dmesg when
fscache is enabled:

    NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)

Fix this by adding a new LSM hook to load fc->security for submount
creation.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
Fixes: 9bc61ab18b ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
Fixes: 779df6a548 ("NFS: Ensure security label is set for root inode")
Tested-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230808-master-v9-1-e0ecde888221@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-15 08:32:30 +02:00
Roberto Sassu
2c085f3a8f smack: Record transmuting in smk_transmuted
smack_dentry_create_files_as() determines whether transmuting should occur
based on the label of the parent directory the new inode will be added to,
and not the label of the directory where it is created.

This helps for example to do transmuting on overlayfs, since the latter
first creates the inode in the working directory, and then moves it to the
correct destination.

However, despite smack_dentry_create_files_as() provides the correct label,
smack_inode_init_security() does not know from passed information whether
or not transmuting occurred. Without this information,
smack_inode_init_security() cannot set SMK_INODE_CHANGED in smk_flags,
which will result in the SMACK64TRANSMUTE xattr not being set in
smack_d_instantiate().

Thus, add the smk_transmuted field to the task_smack structure, and set it
in smack_dentry_create_files_as() to smk_task if transmuting occurred. If
smk_task is equal to smk_transmuted in smack_inode_init_security(), act as
if transmuting was successful but without taking the label from the parent
directory (the inode label was already set correctly from the current
credentials in smack_inode_alloc_security()).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2023-05-11 10:05:39 -07:00
Roberto Sassu
3a3d8fce31 smack: Retrieve transmuting information in smack_inode_getsecurity()
Enhance smack_inode_getsecurity() to retrieve the value for
SMACK64TRANSMUTE from the inode security blob, similarly to SMACK64.

This helps to display accurate values in the situation where the security
labels come from mount options and not from xattrs.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2023-05-11 10:05:38 -07:00
Linus Torvalds
dc7e22a368 Smack updates for v6.4
-----BEGIN PGP SIGNATURE-----
 
 iQJLBAABCAA1FiEEC+9tH1YyUwIQzUIeOKUVfIxDyBEFAmRGv+4XHGNhc2V5QHNj
 aGF1Zmxlci1jYS5jb20ACgkQOKUVfIxDyBE4QxAAkHiCueaplFsGvYhtx6aeajNC
 0ScA84efBMhQJ/jP4FsTh893bGUkbDv+dyasAVOoAdfFPfgpecEOELzhOaaXv5l2
 8pZ1CtTPXU9h5Csg7D6idII/EyzBUkKDCLbrZexT6A6ZEl0xTqY6Pz6/3uee/W4J
 Z/84U1lX/GgI/SzV6JFcO0XYDj2yp7cfdwIzPUHRky5HgPgLm3roB+eZQwONHfYl
 qYX5xAYCxMx6Uqx3kFb+wgXEJ71lFQGBd7zAZsinGqlrH0vIA63BqpxcHPhYTJNl
 9Y/t6Mb9ds2C1CCGhQTPn/m4hcqYcA5oLuhGWNhOeXMX450XBQ4v7nRw45Dkb1Sa
 IPwJTPfuH2I5r5dOW8cGVCrDp5OT+XQJ5OrsIBtdrPxPGX8x6XyaC4DLG3mympC6
 UfBxdP60Jtm/PRuLCX3tX92zzXhFuqt63Gw87b6htlgEPpirJlhZaEiCYKGlshS1
 b6+kMn1snCxqbBvE/jI3FKHp/C8F/lKNnuVRid9J6HkoyABubWMZ3UIAY+SkVw6b
 9BuF8dn+S/HOqPiijDDnwjnnhHFJQg3F8XRCmNP9MsDqfajcwWHs9ik0NLSMfD50
 CXpp3WIZDVGllmNSeYgkkZKuYV+yNbydLU+DaMfWEkOS7euRoaDozShVJdBTRfnV
 7PYZ3V4KhWkNCWXWfbw=
 =Ynnl
 -----END PGP SIGNATURE-----

Merge tag 'Smack-for-6.4' of https://github.com/cschaufler/smack-next

Pull smack updates from Casey Schaufler:
 "There are two changes, one small and one more substantial:

   - Remove of an unnecessary cast

   - The mount option processing introduced with the mount rework makes
     copies of mount option values. There is no good reason to make
     copies of Smack labels, as they are maintained on a list and never
     removed.

     The code now uses pointers to entries on the list, reducing
     processing time and memory use"

* tag 'Smack-for-6.4' of https://github.com/cschaufler/smack-next:
  Smack: Improve mount process memory use
  smack_lsm: remove unnecessary type casting
2023-04-24 11:37:24 -07:00
Casey Schaufler
de93e515db Smack: Improve mount process memory use
The existing mount processing code in Smack makes many unnecessary
copies of Smack labels. Because Smack labels never go away once
imported it is safe to use pointers to them rather than copies.
Replace the use of copies of label names to pointers to the global
label list entries.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2023-04-05 08:46:14 -07:00
Paul Moore
f22f9aaf6c selinux: remove the runtime disable functionality
After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality.  The existing kernel deprecation
notice explains the functionality and why we want to remove it:

  The selinuxfs "disable" node allows SELinux to be disabled at
  runtime prior to a policy being loaded into the kernel.  If
  disabled via this mechanism, SELinux will remain disabled until
  the system is rebooted.

  The preferred method of disabling SELinux is via the "selinux=0"
  boot parameter, but the selinuxfs "disable" node was created to
  make it easier for systems with primitive bootloaders that did not
  allow for easy modification of the kernel command line.
  Unfortunately, allowing for SELinux to be disabled at runtime makes
  it difficult to secure the kernel's LSM hooks using the
  "__ro_after_init" feature.

It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.

From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.

It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.

Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage.  In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-20 12:34:23 -04:00
XU pengfei
502a29b04d smack_lsm: remove unnecessary type casting
Remove unnecessary type casting.
The type of inode variable is struct inode *, so no type casting required.

Signed-off-by: XU pengfei <xupengfei@nfschina.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2023-03-08 09:35:20 -08:00
Linus Torvalds
77bc1bb184 One fix for resetting CIPSO labeling.
-----BEGIN PGP SIGNATURE-----
 
 iQJLBAABCAA1FiEEC+9tH1YyUwIQzUIeOKUVfIxDyBEFAmP1G00XHGNhc2V5QHNj
 aGF1Zmxlci1jYS5jb20ACgkQOKUVfIxDyBFKjxAApRk/kVuNJArDxf+0gruF/5R+
 Ey+8olXAnGELoS2YZeg3pfGyB+BkQjqscAcJTj9zQ8IF7k8CCTP1V9TpcOdV3etU
 8LCyvUMf+dquLcEbEwgWp76iXmKM0dsrizzv0jAz+J9dvmWa7moVZ8mnDIlDMrju
 UfxH6+dHAzqk6HtXqbkMNnQM3+bABaBXP62ba9je8qwdLEoAXSS+MpDMnkPTnVgd
 EtL+W5RiR/AczG4DMpqFJN8HwF0jVloEGp7DLUyAICyU0DLVk9ZObkKO8Tg8FT4e
 krMT6csUXdfrrkIbXEAL7CogQE5chpez2d8IVn3QfipPePxspAPTmfqVX8CclL3o
 Nwudb+h45ZwZ4aM3FE8Na6ZcyNF9bzytmk3SkzcHjgixYDAjRZymVZvMzL2dIFWt
 PlJhMeTWlG9BRVc011K4GEFsNAqwuOhjS/7hIDKXsvXskms+OpNudVlBpyp0wf71
 5lH1595hbZKIndqGcxKtXCMxjbiIn1ZfsbyqMT8onPLRMLlllweGwISyJIK+nMRo
 2nVU9rEWgy8XAiw0sTenbpNvuO4EcDu9pVkj/jA6llgeb4DqLeGWjIWRUY/W30Pp
 +029mpvYM9ZzFFM/U+hI4C+upVq5FqUlcOH63BbbtgCSPigjrvuObbfTa1rxVLMd
 6qQRFQCvJJIgG/QnqD0=
 =QkGV
 -----END PGP SIGNATURE-----

Merge tag 'Smack-for-6.3' of https://github.com/cschaufler/smack-next

Pull smack update from Casey Schaufler:
 "One fix for resetting CIPSO labeling"

* tag 'Smack-for-6.3' of https://github.com/cschaufler/smack-next:
  smackfs: Added check catlen
2023-02-22 12:52:59 -08:00
Denis Arefev
ccfd889acb smackfs: Added check catlen
If the catlen is 0, the memory for the netlbl_lsm_catmap
  structure must be allocated anyway, otherwise the check of
  such rules is not completed correctly.

Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2023-02-21 11:22:02 -08:00
Christian Brauner
700b794052
fs: port acl to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner
39f60c1cce
fs: port xattr to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner
4609e1f18e
fs: port ->permission() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Linus Torvalds
c76ff350bd lsm/stable-6.2 PR 20221212
-----BEGIN PGP SIGNATURE-----
 
 iQJIBAABCAAyFiEES0KozwfymdVUl37v6iDy2pc3iXMFAmOXmxkUHHBhdWxAcGF1
 bC1tb29yZS5jb20ACgkQ6iDy2pc3iXMPXg//cxfYC8lRtVpuGNCZWDietSiHzpzu
 +qFntaTplvybJMQX0HfgNee5cTBZM+W5mp1BHRcZInvV5LRhyrVtgsxDBifutE4x
 LyUJAw5SkiPdRC+XLDIRLKiZCobFBLVs2zO+qibIqsyR60pFjU6WXBLbJfidXBFR
 yWudDbLU0YhQJCHdNHNqnHCgqrEculxn6q3QPvm/DX0xzBwkFHSSYBkGNvHW2ZTA
 lKNreEOwEk5DTLIKjP4bJ72ixp0xbshw5CXuxtwB/12/4h8QbWbJVQLlIeZrTLmp
 zQXQLJ3pCqKJ2OUCgMDK+wmkvLezd80BV3Due7KX0pT0YRDygoh5QEpZ5/8k8eG7
 prxToh2gJWk2htfJF6kgMpAh9Jqewcke4BysbYVM/427OPZYwQqLDZDGOzbtT6pl
 FYF+adN9wwkAErnHnPlzYipUEpBWurbjtsV8KFWNERoZ4YmzfSPEisRqGIHDGRws
 bTyq/7qs5FXkb1zULELj8V+S2ULsmxPqsxJ63p9di54Uo9lHK0I+0IUtajGDdfze
 psAasa9DD/oH2PAbSmpQ5Xo9XyfHRXsVuz1twEmEA14ML0m4wHbNWVHaK0aaXVdG
 kJKSDSjMsiV+GiwNo7ISJ4pVdUpnMI/iZSghFfV28cJslNhJDeaREHaE/Wtn1/xF
 /bCVmEfS16UoJsQ=
 =klFk
 -----END PGP SIGNATURE-----

Merge tag 'lsm-pr-20221212' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

Pull lsm updates from Paul Moore:

 - Improve the error handling in the device cgroup such that memory
   allocation failures when updating the access policy do not
   potentially alter the policy.

 - Some minor fixes to reiserfs to ensure that it properly releases
   LSM-related xattr values.

 - Update the security_socket_getpeersec_stream() LSM hook to take
   sockptr_t values.

   Previously the net/BPF folks updated the getsockopt code in the
   network stack to leverage the sockptr_t type to make it easier to
   pass both kernel and __user pointers, but unfortunately when they did
   so they didn't convert the LSM hook.

   While there was/is no immediate risk by not converting the LSM hook,
   it seems like this is a mistake waiting to happen so this patch
   proactively does the LSM hook conversion.

 - Convert vfs_getxattr_alloc() to return an int instead of a ssize_t
   and cleanup the callers. Internally the function was never going to
   return anything larger than an int and the callers were doing some
   very odd things casting the return value; this patch fixes all that
   and helps bring a bit of sanity to vfs_getxattr_alloc() and its
   callers.

 - More verbose, and helpful, LSM debug output when the system is booted
   with "lsm.debug" on the command line. There are examples in the
   commit description, but the quick summary is that this patch provides
   better information about which LSMs are enabled and the ordering in
   which they are processed.

 - General comment and kernel-doc fixes and cleanups.

* tag 'lsm-pr-20221212' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  lsm: Fix description of fs_context_parse_param
  lsm: Add/fix return values in lsm_hooks.h and fix formatting
  lsm: Clarify documentation of vm_enough_memory hook
  reiserfs: Add missing calls to reiserfs_security_free()
  lsm,fs: fix vfs_getxattr_alloc() return type and caller error paths
  device_cgroup: Roll back to original exceptions after copy failure
  LSM: Better reporting of actual LSMs at boot
  lsm: make security_socket_getpeersec_stream() sockptr_t safe
  audit: Fix some kernel-doc warnings
  lsm: remove obsoleted comments for security hooks
  fs: edit a comment made in bad taste
2022-12-13 09:47:48 -08:00
Paul Moore
b10b9c342f lsm: make security_socket_getpeersec_stream() sockptr_t safe
Commit 4ff09db1b7 ("bpf: net: Change sk_getsockopt() to take the
sockptr_t argument") made it possible to call sk_getsockopt()
with both user and kernel address space buffers through the use of
the sockptr_t type.  Unfortunately at the time of conversion the
security_socket_getpeersec_stream() LSM hook was written to only
accept userspace buffers, and in a desire to avoid having to change
the LSM hook the commit author simply passed the sockptr_t's
userspace buffer pointer.  Since the only sk_getsockopt() callers
at the time of conversion which used kernel sockptr_t buffers did
not allow SO_PEERSEC, and hence the
security_socket_getpeersec_stream() hook, this was acceptable but
also very fragile as future changes presented the possibility of
silently passing kernel space pointers to the LSM hook.

There are several ways to protect against this, including careful
code review of future commits, but since relying on code review to
catch bugs is a recipe for disaster and the upstream eBPF maintainer
is "strongly against defensive programming", this patch updates the
LSM hook, and all of the implementations to support sockptr_t and
safely handle both user and kernel space buffers.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-11-04 23:25:30 -04:00
Christian Brauner
44faac01cd
smack: implement get, set and remove acl hook
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

So far posix acls were passed as a void blob to the security and
integrity modules. Some of them like evm then proceed to interpret the
void pointer and convert it into the kernel internal struct posix acl
representation to perform their integrity checking magic. This is
obviously pretty problematic as that requires knowledge that only the
vfs is guaranteed to have and has lead to various bugs. Add a proper
security hook for setting posix acls and pass down the posix acls in
their appropriate vfs format instead of hacking it through a void
pointer stored in the uapi format.

I spent considerate time in the security module infrastructure and
audited all codepaths. Smack has no restrictions based on the posix
acl values passed through it. The capability hook doesn't need to be
called either because it only has restrictions on security.* xattrs. So
these all becomes very simple hooks for smack.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-20 10:13:29 +02:00
Linus Torvalds
4c0ed7d8d6 whack-a-mole: constifying struct path *
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCYzxmRQAKCRBZ7Krx/gZQ
 6+/kAQD2xyf+i4zOYVBr1NB3qBbhVS1zrni1NbC/kT3dJPgTvwEA7z7eqwnrN4zg
 scKFP8a3yPoaQBfs4do5PolhuSr2ngA=
 =NBI+
 -----END PGP SIGNATURE-----

Merge tag 'pull-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs constification updates from Al Viro:
 "whack-a-mole: constifying struct path *"

* tag 'pull-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ecryptfs: constify path
  spufs: constify path
  nd_jump_link(): constify path
  audit_init_parent(): constify path
  __io_setxattr(): constify path
  do_proc_readlink(): constify path
  overlayfs: constify path
  fs/notify: constify path
  may_linkat(): constify path
  do_sys_name_to_handle(): constify path
  ->getprocattr(): attribute name is const char *, TYVM...
2022-10-06 17:31:02 -07:00
Linus Torvalds
74a0f84590 Smack updates for v6.1
-----BEGIN PGP SIGNATURE-----
 
 iQJLBAABCAA1FiEEC+9tH1YyUwIQzUIeOKUVfIxDyBEFAmMzNOsXHGNhc2V5QHNj
 aGF1Zmxlci1jYS5jb20ACgkQOKUVfIxDyBHSyg//XprfrAxU5Mk13fEKv1+L2TQ5
 07510lqIevJObY9WwhzPwYW/3KZwlXDc8pcYnJZt5o6zV9YXipB4kRtdDVdew5k7
 l+WJzwx+6uQjoHk6GrY7d50PhNFOpe+QPP68zs2iBJMairqpHEhEPbX81b2fhD2v
 7VnWWGhKMS+iYR9SEGldA8NNnPpzz4+1xs7OlT6CEM3pnZFANlR1RCSsr1DvYFvZ
 mJEXVWZNGQsLrwKLLesYGBzRRJeZtU47VMROyOqiXgSh+D2p9Z4ajVzdROSVNENY
 8e2CRp2al9Ij0arUBaq1JaAIrvoO2P0YiOSa5wPU2yghj3McvAkIphQ8+c1PxkzM
 r8Qk3hyZfjDMbh3jBFEugXt+UaQCCqELWnCrxoWZVflUdi5YXT1/7STifsQ1DhOw
 okppOmAXsQ7rsr3+GW0249i7ySzvXCI/xtXfpvnT4aw0rjBML0uN7GeoEzPr84Pw
 2vPM0lhULLifvfoaUwkySYVt0VHS2LVk1xaNFVikM80rkFagAjqU4ouzZw0JCa2U
 VA45/h5/kWt+57uj8hdmaPZtfkw7saSl51kozwISltJS7ga6X6lCm1VwWZC6bjJF
 QGUXWZlMC1hgwYK4DmMvjr9wWIwkxmEcVWSBMmsHiacr1Rl5N0Lnq0Rp8xD15u/R
 TIdvYo9hHV6biX9+pkU=
 =rKZK
 -----END PGP SIGNATURE-----

Merge tag 'Smack-for-6.1' of https://github.com/cschaufler/smack-next

Pull smack updates from Casey Schaufler:
 "Two minor code clean-ups: one removes constants left over from the old
  mount API, while the other gets rid of an unneeded variable.

  The other change fixes a flaw in handling IPv6 labeling"

* tag 'Smack-for-6.1' of https://github.com/cschaufler/smack-next:
  smack: cleanup obsolete mount option flags
  smack: lsm: remove the unneeded result variable
  SMACK: Add sk_clone_security LSM hook
2022-10-03 17:38:09 -07:00
Xiu Jianfeng
cc71271f5b smack: cleanup obsolete mount option flags
These mount option flags are obsolete since commit 12085b14a4 ("smack:
switch to private smack_mnt_opts"), remove them.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-09-27 10:33:03 -07:00
Xu Panda
d3f84f5c96 smack: lsm: remove the unneeded result variable
Return the value smk_ptrace_rule_check() directly instead of storing it
in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-09-27 10:33:03 -07:00
Lontke Michael
4ca165fc6c SMACK: Add sk_clone_security LSM hook
Using smk_of_current() during sk_alloc_security hook leads in
rare cases to a faulty initialization of the security context
of the created socket.

By adding the LSM hook sk_clone_security to SMACK this initialization
fault is corrected by copying the security context of the old socket
pointer to the newly cloned one.

Co-authored-by: Martin Ostertag: <martin.ostertag@elektrobit.com>
Signed-off-by: Lontke Michael <michael.lontke@elektrobit.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-09-27 10:33:03 -07:00
Al Viro
c8e477c649 ->getprocattr(): attribute name is const char *, TYVM...
cast of ->d_name.name to char * is completely wrong - nothing is
allowed to modify its contents.

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-09-01 17:34:39 -04:00
Casey Schaufler
dd93734022 Smack: Provide read control for io_uring_cmd
Limit io_uring "cmd" options to files for which the caller has
Smack read access. There may be cases where the cmd option may
be closer to a write access than a read, but there is no way
to make that determination.

Cc: stable@vger.kernel.org
Fixes: ee692a21e9 ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-26 14:56:35 -04:00
Xiu Jianfeng
aa16fb4b9e smack: Remove the redundant lsm_inode_alloc
It's not possible for inode->i_security to be NULL here because every
inode will call inode_init_always and then lsm_inode_alloc to alloc
memory for inode->security, this is what LSM infrastructure management
do, so remove this redundant code.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-08-01 11:26:09 -07:00
GONG, Ruiqi
63c3b5d2ca smack: Replace kzalloc + strncpy with kstrndup
Simplify the code by using kstrndup instead of kzalloc and strncpy in
smk_parse_smack(), which meanwhile remove strncpy as [1] suggests.

[1]: https://github.com/KSPP/linux/issues/90

Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-08-01 11:26:09 -07:00
Linus Torvalds
cbd76edeab Cleanups (and one fix) around struct mount handling.
The fix is usermode_driver.c one - once you've done kern_mount(), you
 must kern_unmount(); simple mntput() will end up with a leak.  Several
 failure exits in there messed up that way...  In practice you won't
 hit those particular failure exits without fault injection, though.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCYpvrWQAKCRBZ7Krx/gZQ
 6z29AP9EZVSyIvnwXleehpa2mEZhsp+KAKgV/ENaKHMn7jiH0wD/bfgnhxIDNuc5
 108E2R5RWEYTynW5k7nnP5PsTsMq5Qc=
 =b3Wc
 -----END PGP SIGNATURE-----

Merge tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull mount handling updates from Al Viro:
 "Cleanups (and one fix) around struct mount handling.

  The fix is usermode_driver.c one - once you've done kern_mount(), you
  must kern_unmount(); simple mntput() will end up with a leak. Several
  failure exits in there messed up that way... In practice you won't hit
  those particular failure exits without fault injection, though"

* tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  move mount-related externs from fs.h to mount.h
  blob_to_mnt(): kern_unmount() is needed to undo kern_mount()
  m->mnt_root->d_inode->i_sb is a weird way to spell m->mnt_sb...
  linux/mount.h: trim includes
  uninline may_mount() and don't opencode it in fspick(2)/fsopen(2)
2022-06-04 19:00:05 -07:00
Michal Orzel
eaff451d4b smack: Remove redundant assignments
Get rid of redundant assignments which end up in values not being
read either because they are overwritten or the function ends.

Reported by clang-tidy [deadcode.DeadStores]

Signed-off-by: Michal Orzel <michalorzel.eng@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-05-23 11:12:08 -07:00
Al Viro
70f8d9c575 move mount-related externs from fs.h to mount.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-05-19 23:25:48 -04:00
Casey Schaufler
a5cd1ab7ab Fix incorrect type in assignment of ipv6 port for audit
Remove inappropriate use of ntohs() and assign the
port value directly.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-02-28 15:45:32 -08:00
Paul Moore
6326948f94 lsm: security_task_getsecid_subj() -> security_current_getsecid_subj()
The security_task_getsecid_subj() LSM hook invites misuse by allowing
callers to specify a task even though the hook is only safe when the
current task is referenced.  Fix this by removing the task_struct
argument to the hook, requiring LSM implementations to use the
current task.  While we are changing the hook declaration we also
rename the function to security_current_getsecid_subj() in an effort
to reinforce that the hook captures the subjective credentials of the
current task and not an arbitrary task on the system.

Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-11-22 17:52:47 -05:00
Linus Torvalds
cdab10bf32 selinux/stable-5.16 PR 20211101
-----BEGIN PGP SIGNATURE-----
 
 iQJIBAABCAAyFiEES0KozwfymdVUl37v6iDy2pc3iXMFAmGANbAUHHBhdWxAcGF1
 bC1tb29yZS5jb20ACgkQ6iDy2pc3iXNaMBAAg+9gZr0F7xiafu8JFZqZfx/AQdJ2
 G2cn3le+/tXGZmF8m/+82lOaR6LeQLatgSDJNSkXWkKr0nRwseQJDbtRfvYJdn0t
 Ax05/Fmz6OGxQ2wgRYgaFiSrKpE5p3NhDtiLFVdkCJaQNe/8DZOc7NhBl6EjZf3x
 ubhl2hUiJ4AmiXGwcYhr4uKgP4nhW8OM1/OkskVi+bBMmLA8KTY9kslmIDP5E3BW
 29W4qhqeLNQupY5dGMEMVcyxY9ZUWpO39q4uOaQVZrUGE7xABkj/jhnxT5gFTSlI
 pu8VhsYXm9KuRVveIsv0L5SZfadwoM9YAl7ki1wD3W5rHqOAte3rBTm6VmNlQwfU
 MqxP65Jiyxudxet5Be3/dCRH/+MDQuwBxivgmZXbeVxor2SeznVb0GDaEUC5FSHu
 CJIgWtQzsPJMxgAEGXN4F3QGP0htTTJni56GUPOsrf4TIBW02TT+oLTLFRIokQQL
 INNOfwVSRXElnCsvxsHR4oB+JZ9pJyBaAmeupcQ6jmcKiWlbLj4s+W0U0pM5h91v
 hmMpz7KMxrX6gVL4gB2Jj4aN3r5YRbq26NBu6D+wdwwBTeTTocaHSpAqkv4buClf
 uNk3cG8Hkp8TTg9cM8jYgpxMyzKH/AI/Uw3VhEa1xCiq2Ck3DgfnZvnvcRRaZevU
 FPgmwgqePJXGi60=
 =sb8J
 -----END PGP SIGNATURE-----

Merge tag 'selinux-pr-20211101' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:

 - Add LSM/SELinux/Smack controls and auditing for io-uring.

   As usual, the individual commit descriptions have more detail, but we
   were basically missing two things which we're adding here:

      + establishment of a proper audit context so that auditing of
        io-uring ops works similarly to how it does for syscalls (with
        some io-uring additions because io-uring ops are *not* syscalls)

      + additional LSM hooks to enable access control points for some of
        the more unusual io-uring features, e.g. credential overrides.

   The additional audit callouts and LSM hooks were done in conjunction
   with the io-uring folks, based on conversations and RFC patches
   earlier in the year.

 - Fixup the binder credential handling so that the proper credentials
   are used in the LSM hooks; the commit description and the code
   comment which is removed in these patches are helpful to understand
   the background and why this is the proper fix.

 - Enable SELinux genfscon policy support for securityfs, allowing
   improved SELinux filesystem labeling for other subsystems which make
   use of securityfs, e.g. IMA.

* tag 'selinux-pr-20211101' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  security: Return xattr name from security_dentry_init_security()
  selinux: fix a sock regression in selinux_ip_postroute_compat()
  binder: use cred instead of task for getsecid
  binder: use cred instead of task for selinux checks
  binder: use euid from cred instead of using task
  LSM: Avoid warnings about potentially unused hook variables
  selinux: fix all of the W=1 build warnings
  selinux: make better use of the nf_hook_state passed to the NF hooks
  selinux: fix race condition when computing ocontext SIDs
  selinux: remove unneeded ipv6 hook wrappers
  selinux: remove the SELinux lockdown implementation
  selinux: enable genfscon labeling for securityfs
  Smack: Brutalist io_uring support
  selinux: add support for the io_uring access controls
  lsm,io_uring: add LSM hooks to io_uring
  io_uring: convert io_uring to the secure anon inode interface
  fs: add anon_inode_getfile_secure() similar to anon_inode_getfd_secure()
  audit: add filtering for io_uring records
  audit,io_uring,io-wq: add some basic audit support to io_uring
  audit: prepare audit_context for use in calling contexts beyond syscalls
2021-11-01 21:06:18 -07:00
Linus Torvalds
6f2b76a4a3 Smack changes for 5.16
Multiple corrections to smackfs.
 W=1 fixes
 Fix for overlayfs.
 -----BEGIN PGP SIGNATURE-----
 
 iQJLBAABCAA1FiEEC+9tH1YyUwIQzUIeOKUVfIxDyBEFAmGALSwXHGNhc2V5QHNj
 aGF1Zmxlci1jYS5jb20ACgkQOKUVfIxDyBECcRAAuFN3uiptwLHC0P/Yy5VtANF4
 kvRV7egXeIp8tYl6zVb+VIa3AgQMTB0BfdpSVMq8YyTtp5olczlM2b00zN4cVZq0
 VO7XlTUfoljdsi4IysaA5rZZtjT5entoNl6eiCrMVwpvC4ZrlTqebOJteXDAnEQP
 zI+smzc5mUFn1FUkGaQ+ciLHv2wyT39Wmk78BDKI/UAl09xV6Kxfci15Q9UPpZ94
 CnYMfrjsinUCzQ+gbj9FIe5vXvcGwVoO7jJUNda5kuCSM3N4TTxD/fDkVxWEwOD2
 eNjemub5RkxVWSlzRtVQgEFsssRsd6VYEKop34jyojDOGDj+JVQ03ntnFUfWScUz
 8BkwyYsE8I+f878f0wAaz+8xrefjnwnRUHFzkF5hd6wLFCvQlCKULL/naRtig7pJ
 x1V6Q+AC/Qyu0rNrSH5UCDgsvDQ3YzKocWhnvgCqJa8bd/QlfMKu8sxIwetNlctz
 +TG+GwBLKaVmdiwWoI/CF3PkM4xYo4DtJtDnvlzAiEjGEYosEXilgDBq6IAD8vLa
 cuSXtWCIpBk5VKkglvAvsIbXxnWa0W45j7PXyf8b7YXRWF511I8zBHjpDx6XP/Ko
 FywGEaRDeNO3KZJxw9e39FUdyl1MT+s+gN3sERomUTig9RaPhp87pC/kWMWxVj+Y
 fU/iIgrRTqa2spQgYNg=
 =lPZg
 -----END PGP SIGNATURE-----

Merge tag 'Smack-for-5.16' of https://github.com/cschaufler/smack-next

Pull smack updates from Casey Schaufler:
 "Multiple corrections to smackfs:

   - a change for overlayfs support that corrects the initial attributes
     on created files

   - code clean-up for netlabel processing

   - several fixes in smackfs for a variety of reasons

   - Errors reported by W=1 have been addressed

  All told, nothing challenging"

* tag 'Smack-for-5.16' of https://github.com/cschaufler/smack-next:
  smackfs: use netlbl_cfg_cipsov4_del() for deleting cipso_v4_doi
  smackfs: use __GFP_NOFAIL for smk_cipso_doi()
  Smack: fix W=1 build warnings
  smack: remove duplicated hook function
  Smack:- Use overlay inode label in smack_inode_copy_up()
  smack: Guard smack_ipv6_lock definition within a SMACK_IPV6_PORT_LABELING block
  smackfs: Fix use-after-free in netlbl_catmap_walk()
2021-11-01 17:34:02 -07:00
Tetsuo Handa
0934ad42bb smackfs: use netlbl_cfg_cipsov4_del() for deleting cipso_v4_doi
syzbot is reporting UAF at cipso_v4_doi_search() [1], for smk_cipso_doi()
is calling kfree() without removing from the cipso_v4_doi_list list after
netlbl_cfg_cipsov4_map_add() returned an error. We need to use
netlbl_cfg_cipsov4_del() in order to remove from the list and wait for
RCU grace period before kfree().

Link: https://syzkaller.appspot.com/bug?extid=93dba5b91f0fed312cbd [1]
Reported-by: syzbot <syzbot+93dba5b91f0fed312cbd@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6c2e8ac095 ("netlabel: Update kernel configuration API")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-10-22 08:46:53 -07:00
Tetsuo Handa
f91488ee15 smackfs: use __GFP_NOFAIL for smk_cipso_doi()
syzbot is reporting kernel panic at smk_cipso_doi() due to memory
allocation fault injection [1]. The reason for need to use panic() was
not explained. But since no fix was proposed for 18 months, for now
let's use __GFP_NOFAIL for utilizing syzbot resource on other bugs.

Link: https://syzkaller.appspot.com/bug?extid=89731ccb6fec15ce1c22 [1]
Reported-by: syzbot <syzbot+89731ccb6fec15ce1c22@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-10-22 08:46:44 -07:00
Casey Schaufler
b57d02091b Smack: fix W=1 build warnings
A couple of functions had malformed comment blocks.
Namespace parameters were added without updating the
comment blocks. These are all repaired in the Smack code,
so "% make W=1 security/smack" is warning free.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-10-13 14:56:43 -07:00
Florian Westphal
f8de49ef92 smack: remove duplicated hook function
ipv4 and ipv6 hook functions are identical, remove one.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-10-12 08:23:52 -07:00
Vishal Goel
387ef96446 Smack:- Use overlay inode label in smack_inode_copy_up()
Currently in "smack_inode_copy_up()" function, process label is
changed with the label on parent inode. Due to which,
process is assigned directory label and whatever file or directory
created by the process are also getting directory label
which is wrong label.

Changes has been done to use label of overlay inode instead
of parent inode.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-09-28 13:29:40 -07:00
Sebastian Andrzej Siewior
222a96b31c smack: Guard smack_ipv6_lock definition within a SMACK_IPV6_PORT_LABELING block
The mutex smack_ipv6_lock is only used with the SMACK_IPV6_PORT_LABELING
block but its definition is outside of the block. This leads to a
defined-but-not-used warning on PREEMPT_RT.

Moving smack_ipv6_lock down to the block where it is used where it used
raises the question why is smk_ipv6_port_list read if nothing is added
to it.
Turns out, only smk_ipv6_port_check() is using it outside of an ifdef
SMACK_IPV6_PORT_LABELING block. However two of three caller invoke
smk_ipv6_port_check() from a ifdef block and only one is using
__is_defined() macro which requires the function and smk_ipv6_port_list
to be around.

Put the lock and list inside an ifdef SMACK_IPV6_PORT_LABELING block to
avoid the warning regarding unused mutex. Extend the ifdef-block to also
cover smk_ipv6_port_check(). Make smack_socket_connect() use ifdef
instead of __is_defined() to avoid complains about missing function.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-09-24 13:14:49 -07:00
Paul Moore
a3727a8bac selinux,smack: fix subjective/objective credential use mixups
Jann Horn reported a problem with commit eb1231f73c ("selinux:
clarify task subjective and objective credentials") where some LSM
hooks were attempting to access the subjective credentials of a task
other than the current task.  Generally speaking, it is not safe to
access another task's subjective credentials and doing so can cause
a number of problems.

Further, while looking into the problem, I realized that Smack was
suffering from a similar problem brought about by a similar commit
1fb057dcde ("smack: differentiate between subjective and objective
task credentials").

This patch addresses this problem by restoring the use of the task's
objective credentials in those cases where the task is other than the
current executing task.  Not only does this resolve the problem
reported by Jann, it is arguably the correct thing to do in these
cases.

Cc: stable@vger.kernel.org
Fixes: eb1231f73c ("selinux: clarify task subjective and objective credentials")
Fixes: 1fb057dcde ("smack: differentiate between subjective and objective task credentials")
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-09-23 12:30:59 -04:00
Casey Schaufler
d9d8c93938 Smack: Brutalist io_uring support
Add Smack privilege checks for io_uring. Use CAP_MAC_OVERRIDE
for the override_creds case and CAP_MAC_ADMIN for creating a
polling thread. These choices are based on conjecture regarding
the intent of the surrounding code.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: make the smack_uring_* funcs static, remove debug code]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-09-19 22:40:51 -04:00
Pawan Gupta
0817534ff9 smackfs: Fix use-after-free in netlbl_catmap_walk()
Syzkaller reported use-after-free bug as described in [1]. The bug is
triggered when smk_set_cipso() tries to free stale category bitmaps
while there are concurrent reader(s) using the same bitmaps.

Wait for RCU grace period to finish before freeing the category bitmaps
in smk_set_cipso(). This makes sure that there are no more readers using
the stale bitmaps and freeing them should be safe.

[1] https://lore.kernel.org/netdev/000000000000a814c505ca657a4e@google.com/

Reported-by: syzbot+3f91de0b813cc3d19a80@syzkaller.appspotmail.com
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-09-15 16:42:25 -07:00
Austin Kim
bfc3cac0c7 smack: mark 'smack_enabled' global variable as __initdata
Mark 'smack_enabled' as __initdata
since it is only used during initialization code.

Signed-off-by: Austin Kim <austin.kim@lge.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-07-20 10:34:59 -07:00
Tianjia Zhang
6d14f5c702 Smack: Fix wrong semantics in smk_access_entry()
In the smk_access_entry() function, if no matching rule is found
in the rust_list, a negative error code will be used to perform bit
operations with the MAY_ enumeration value. This is semantically
wrong. This patch fixes this issue.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-07-20 09:17:36 -07:00
ChenXiaoSong
fe6bde732b Smack: fix doc warning
Fix gcc W=1 warning:

security/smack/smack_access.c:342: warning: Function parameter or member 'ad' not described in 'smack_log'
security/smack/smack_access.c:403: warning: Function parameter or member 'skp' not described in 'smk_insert_entry'
security/smack/smack_access.c:487: warning: Function parameter or member 'level' not described in 'smk_netlbl_mls'
security/smack/smack_access.c:487: warning: Function parameter or member 'len' not described in 'smk_netlbl_mls'

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-06-08 10:23:08 -07:00
Jens Axboe
0169d8f33a Revert "Smack: Handle io_uring kernel thread privileges"
This reverts commit 942cb357ae.

The io_uring PF_IO_WORKER threads no longer have PF_KTHREAD set, so no
need to special case them for credential checks.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-05-18 10:36:48 -07:00
Tetsuo Handa
49ec114a6e smackfs: restrict bytes count in smk_set_cipso()
Oops, I failed to update subject line.

From 07571157c91b98ce1a4aa70967531e64b78e8346 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 12 Apr 2021 22:25:06 +0900
Subject: [PATCH] smackfs: restrict bytes count in smk_set_cipso()

Commit 7ef4c19d24 ("smackfs: restrict bytes count in smackfs write
functions") missed that count > SMK_CIPSOMAX check applies to only
format == SMK_FIXED24_FMT case.

Reported-by: syzbot <syzbot+77c53db50c9fff774e8e@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-05-10 13:55:08 -07:00
Xiong Zhenwu
2e08fb550a security/smack/: fix misspellings using codespell tool
A typo is found out by codespell tool in 383th line of smackfs.c:

$ codespell ./security/smack/
./smackfs.c:383: numer  ==> number

Fix a typo found by codespell.

Signed-off-by: Xiong Zhenwu <xiong.zhenwu@zte.com.cn>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-05-10 13:54:58 -07:00
Linus Torvalds
17ae69aba8 Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com>
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEgycj0O+d1G2aycA8rZhLv9lQBTwFAmCInP4ACgkQrZhLv9lQ
 BTza0g//dTeb9woC9H7qlEhK4l9yk62lTss60Q8X7m7ZSNfdL4tiEbi64SgK+iOW
 OOegbrOEb8Kzh4KJJYmVlVZ5YUWyH4szgmee1wnylBdsWiWaPLPF3Cflz77apy6T
 TiiBsJd7rRE29FKheaMt34B41BMh8QHESN+DzjzJWsFoi/uNxjgSs2W16XuSupKu
 bpRmB1pYNXMlrkzz7taL05jndZYE5arVriqlxgAsuLOFOp/ER7zecrjImdCM/4kL
 W6ej0R1fz2Geh6CsLBJVE+bKWSQ82q5a4xZEkSYuQHXgZV5eywE5UKu8ssQcRgQA
 VmGUY5k73rfY9Ofupf2gCaf/JSJNXKO/8Xjg0zAdklKtmgFjtna5Tyg9I90j7zn+
 5swSpKuRpilN8MQH+6GWAnfqQlNoviTOpFeq3LwBtNVVOh08cOg6lko/bmebBC+R
 TeQPACKS0Q0gCDPm9RYoU1pMUuYgfOwVfVRZK1prgi2Co7ZBUMOvYbNoKYoPIydr
 ENBYljlU1OYwbzgR2nE+24fvhU8xdNOVG1xXYPAEHShu+p7dLIWRLhl8UCtRQpSR
 1ofeVaJjgjrp29O+1OIQjB2kwCaRdfv/Gq1mztE/VlMU/r++E62OEzcH0aS+mnrg
 yzfyUdI8IFv1q6FGT9yNSifWUWxQPmOKuC8kXsKYfqfJsFwKmHM=
 =uCN4
 -----END PGP SIGNATURE-----

Merge tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull Landlock LSM from James Morris:
 "Add Landlock, a new LSM from Mickaël Salaün.

  Briefly, Landlock provides for unprivileged application sandboxing.

  From Mickaël's cover letter:
    "The goal of Landlock is to enable to restrict ambient rights (e.g.
     global filesystem access) for a set of processes. Because Landlock
     is a stackable LSM [1], it makes possible to create safe security
     sandboxes as new security layers in addition to the existing
     system-wide access-controls. This kind of sandbox is expected to
     help mitigate the security impact of bugs or unexpected/malicious
     behaviors in user-space applications. Landlock empowers any
     process, including unprivileged ones, to securely restrict
     themselves.

     Landlock is inspired by seccomp-bpf but instead of filtering
     syscalls and their raw arguments, a Landlock rule can restrict the
     use of kernel objects like file hierarchies, according to the
     kernel semantic. Landlock also takes inspiration from other OS
     sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD
     Pledge/Unveil.

     In this current form, Landlock misses some access-control features.
     This enables to minimize this patch series and ease review. This
     series still addresses multiple use cases, especially with the
     combined use of seccomp-bpf: applications with built-in sandboxing,
     init systems, security sandbox tools and security-oriented APIs [2]"

  The cover letter and v34 posting is here:

      https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/

  See also:

      https://landlock.io/

  This code has had extensive design discussion and review over several
  years"

Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1]
Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2]

* tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  landlock: Enable user space to infer supported features
  landlock: Add user and kernel documentation
  samples/landlock: Add a sandbox manager example
  selftests/landlock: Add user space tests
  landlock: Add syscall implementations
  arch: Wire up Landlock syscalls
  fs,security: Add sb_delete hook
  landlock: Support filesystem access-control
  LSM: Infrastructure management of the superblock
  landlock: Add ptrace restrictions
  landlock: Set up the security framework and manage credentials
  landlock: Add ruleset and domain management
  landlock: Add object management
2021-05-01 18:50:44 -07:00
Casey Schaufler
1aea780837 LSM: Infrastructure management of the superblock
Move management of the superblock->sb_security blob out of the
individual security modules and into the security infrastructure.
Instead of allocating the blobs from within the modules, the modules
tell the infrastructure how much space is required, and the space is
allocated there.

Cc: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-6-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-04-22 12:22:10 -07:00
Paul Moore
1fb057dcde smack: differentiate between subjective and objective task credentials
With the split of the security_task_getsecid() into subjective and
objective variants it's time to update Smack to ensure it is using
the correct task creds.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-03-22 15:24:14 -04:00
Paul Moore
4ebd7651bf lsm: separate security_task_getsecid() into subjective and objective variants
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>
2021-03-22 15:23:32 -04:00