linux-stable.git/security/integrity/ima, branch v6.3

Merge tag 'integrity-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2023-02-22T20:36:25+00:00

Pull integrity update from Mimi Zohar:
 "One doc and one code cleanup, and two bug fixes"

* tag 'integrity-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: Introduce MMAP_CHECK_REQPROT hook
  ima: Align ima_file_mmap() parameters with mmap_file LSM hook
  evm: call dump_security_xattr() in all cases to remove code duplication
  ima: fix ima_delete_rules() kernel-doc warning
  ima: return IMA digest value only when IMA_COLLECTED flag is set
  ima: fix error handling logic when file measurement failed

ima: Introduce MMAP_CHECK_REQPROT hook

2023-01-31T18:08:39+00:00

Commit 98de59bfe4b2f ("take calculation of final prot in
security_mmap_file() into a helper") caused ima_file_mmap() to receive the
protections requested by the application and not those applied by the
kernel.

After restoring the original MMAP_CHECK behavior, existing attestation
servers might be broken due to not being ready to handle new entries
(previously missing) in the IMA measurement list.

Restore the original correct MMAP_CHECK behavior, instead of keeping the
current buggy one and introducing a new hook with the correct behavior.
Otherwise, there would have been the risk of IMA users not noticing the
problem at all, as they would actively have to update the IMA policy, to
switch to the correct behavior.

Also, introduce the new MMAP_CHECK_REQPROT hook to keep the current
behavior, so that IMA users could easily fix a broken attestation server,
although this approach is discouraged due to potentially missing
measurements.

Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar

ima: Align ima_file_mmap() parameters with mmap_file LSM hook

2023-01-31T18:08:38+00:00

Commit 98de59bfe4b2f ("take calculation of final prot in
security_mmap_file() into a helper") moved the code to update prot, to be
the actual protections applied to the kernel, to a new helper called
mmap_prot().

However, while without the helper ima_file_mmap() was getting the updated
prot, with the helper ima_file_mmap() gets the original prot, which
contains the protections requested by the application.

A possible consequence of this change is that, if an application calls
mmap() with only PROT_READ, and the kernel applies PROT_EXEC in addition,
that application would have access to executable memory without having this
event recorded in the IMA measurement list. This situation would occur for
example if the application, before mmap(), calls the personality() system
call with READ_IMPLIES_EXEC as the first argument.

Align ima_file_mmap() parameters with those of the mmap_file LSM hook, so
that IMA can receive both the requested prot and the final prot. Since the
requested protections are stored in a new variable, and the final
protections are stored in the existing variable, this effectively restores
the original behavior of the MMAP_CHECK hook.

Cc: stable@vger.kernel.org
Fixes: 98de59bfe4b2 ("take calculation of final prot in security_mmap_file() into a helper")
Signed-off-by: Roberto Sassu 
Reviewed-by: Stefan Berger 
Signed-off-by: Mimi Zohar

fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap

2023-01-19T08:24:29+00:00

Convert to struct mnt_idmap.
Remove legacy file_mnt_user_ns() and mnt_user_ns().

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("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 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

fs: port acl to mnt_idmap

2023-01-19T08:24:28+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("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 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

fs: port xattr to mnt_idmap

2023-01-19T08:24:28+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("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 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

fs: port ->permission() to pass mnt_idmap

2023-01-19T08:24:28+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("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 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

ima: fix ima_delete_rules() kernel-doc warning

2023-01-18T18:35:40+00:00

Use correct kernel-doc syntax in the function description to
prevent a kernel-doc warning:

security/integrity/ima/ima_policy.c:1964: warning: expecting prototype for ima_delete_rules() called to cleanup invalid in(). Prototype was for ima_delete_rules() instead

Signed-off-by: Randy Dunlap 
Reviewed-by: Paul Moore 
Signed-off-by: Mimi Zohar

ima: return IMA digest value only when IMA_COLLECTED flag is set

2023-01-18T18:21:50+00:00

The IMA_COLLECTED flag indicates whether the IMA subsystem has
successfully collected a measurement for a given file object. Ensure
that we return the respective digest value stored within the iint
entry only when this flag has been set.

Failing to check for the presence of this flag exposes consumers of
this IMA API to receive potentially undesired IMA digest values when
an erroneous condition has been experienced in some of the lower level
IMA API code.

Signed-off-by: Matt Bobrowski 
Signed-off-by: Mimi Zohar

ima: fix error handling logic when file measurement failed

2023-01-18T18:17:00+00:00

Restore the error handling logic so that when file measurement fails,
the respective iint entry is not left with the digest data being
populated with zeroes.

Fixes: 54f03916fb89 ("ima: permit fsverity's file digests in the IMA measurement list")
Cc: stable@vger.kernel.org	# 5.19
Signed-off-by: Matt Bobrowski 
Signed-off-by: Mimi Zohar