kernel/linux.git/security/integrity/ima/ima_api.c, branch v6.6.131

ima: Fix use-after-free on a dentry's dname.name

2024-06-21T12:38:48+00:00

commit be84f32bb2c981ca670922e047cdde1488b233de upstream. ->d_name.name can change on rename and the earlier value can be freed; there are conditions sufficient to stabilize it (->d_lock on dentry, ->d_lock on its parent, ->i_rwsem exclusive on the parent's inode, rename_lock), but none of those are met at any of the sites. Take a stable snapshot of the name instead. Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/ Signed-off-by: Al Viro Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

ima: detect changes to the backing overlay file

2023-11-28T17:20:03+00:00

commit b836c4d29f2744200b2af41e14bf50758dddc818 upstream. Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for IMA") forced signature re-evaulation on every file access. Instead of always re-evaluating the file's integrity, detect a change to the backing file, by comparing the cached file metadata with the backing file's metadata. Verifying just the i_version has not changed is insufficient. In addition save and compare the i_ino and s_dev as well. Reviewed-by: Amir Goldstein Tested-by: Eric Snowberg Tested-by: Raul E Rangel Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

Merge tag 'integrity-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2023-06-28T00:32:34+00:00

Pull integrity subsystem updates from Mimi Zohar: "An i_version change, one bug fix, and three kernel doc fixes: - instead of IMA detecting file change by directly accesssing i_version, it now calls vfs_getattr_nosec(). - fix a race condition when inserting a new node in the iint rb-tree" * tag 'integrity-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: ima: Fix build warnings evm: Fix build warnings evm: Complete description of evm_inode_setattr() integrity: Fix possible multiple allocation in integrity_inode_get() IMA: use vfs_getattr_nosec to get the i_version

fsverity: rework fsverity_get_digest() again

2023-06-14T17:41:07+00:00

Address several issues with the calling convention and documentation of fsverity_get_digest(): - Make it provide the hash algorithm as either a FS_VERITY_HASH_ALG_* value or HASH_ALGO_* value, at the caller's choice, rather than only a HASH_ALGO_* value as it did before. This allows callers to work with the fsverity native algorithm numbers if they want to. HASH_ALGO_* is what IMA uses, but other users (e.g. overlayfs) should use FS_VERITY_HASH_ALG_* to match fsverity-utils and the fsverity UAPI. - Make it return the digest size so that it doesn't need to be looked up separately. Use the return value for this, since 0 works nicely for the "file doesn't have fsverity enabled" case. This also makes it clear that no other errors are possible. - Rename the 'digest' parameter to 'raw_digest' and clearly document that it is only useful in combination with the algorithm ID. This hopefully clears up a point of confusion. - Export it to modules, since overlayfs will need it for checking the fsverity digests of lowerdata files (https://lore.kernel.org/r/dd294a44e8f401e6b5140029d8355f88748cd8fd.1686565330.git.alexl@redhat.com). Acked-by: Mimi Zohar # for the IMA piece Link: https://lore.kernel.org/r/20230612190047.59755-1-ebiggers@kernel.org Signed-off-by: Eric Biggers

IMA: use vfs_getattr_nosec to get the i_version

2023-05-23T22:07:34+00:00

IMA currently accesses the i_version out of the inode directly when it does a measurement. This is fine for most simple filesystems, but can be problematic with more complex setups (e.g. overlayfs). Make IMA instead call vfs_getattr_nosec to get this info. This allows the filesystem to determine whether and how to report the i_version, and should allow IMA to work properly with a broader class of filesystems in the future. Reported-and-Tested-by: Stefan Berger Reviewed-by: Christian Brauner Signed-off-by: Jeff Layton Signed-off-by: Mimi Zohar

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

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)

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

ima: permit fsverity's file digests in the IMA measurement list

2022-05-05T15:49:13+00:00

Permit fsverity's file digest (a hash of struct fsverity_descriptor) to be included in the IMA measurement list, based on the new measurement policy rule 'digest_type=verity' option. To differentiate between a regular IMA file hash from an fsverity's file digest, use the new d-ngv2 format field included in the ima-ngv2 template. The following policy rule requires fsverity file digests and specifies the new 'ima-ngv2' template, which contains the new 'd-ngv2' field. The policy rule may be constrained, for example based on a fsuuid or LSM label. measure func=FILE_CHECK digest_type=verity template=ima-ngv2 Acked-by: Stefan Berger Signed-off-by: Mimi Zohar