kernel/security/integrity/evm/evm_crypto.c, branch linux-rolling-stable

evm: Use ordered xattrs list to calculate HMAC in evm_init_hmac()

2026-02-26T22:59:14Z

[ Upstream commit 0496fc9cdc384f67be4413b1c6156eb64fccd5c4 ] Commit 8e5d9f916a96 ("smack: deduplicate xattr setting in smack_inode_init_security()") introduced xattr_dupval() to simplify setting the xattrs to be provided by the SMACK LSM on inode creation, in the smack_inode_init_security(). Unfortunately, moving lsm_get_xattr_slot() caused the SMACK64TRANSMUTE xattr be added in the array of new xattrs before SMACK64. This causes the HMAC of xattrs calculated by evm_init_hmac() for new files to diverge from the one calculated by both evm_calc_hmac_or_hash() and evmctl. evm_init_hmac() calculates the HMAC of the xattrs of new files based on the order LSMs provide them, while evm_calc_hmac_or_hash() and evmctl calculate the HMAC based on an ordered xattrs list. Fix the issue by making evm_init_hmac() calculate the HMAC of new files based on the ordered xattrs list too. Fixes: 8e5d9f916a96 ("smack: deduplicate xattr setting in smack_inode_init_security()") Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

integrity: fix typos and spelling errors

2025-02-05T02:36:43Z

Fix typos and spelling errors in integrity module comments that were identified using the codespell tool. No functional changes - documentation only. Signed-off-by: Tanya Agarwal Reviewed-by: Mimi Zohar Signed-off-by: Mimi Zohar

evm: Store and detect metadata inode attributes changes

2024-04-09T21:14:57Z

On stacked filesystem the metadata inode may be different than the one file data inode and therefore changes to it need to be detected independently. Therefore, store the i_version, device number, and inode number associated with the file metadata inode. Implement a function to detect changes to the inode and if a change is detected reset the evm_status. This function will be called by IMA when IMA detects that the metadata inode is different from the file's inode. Co-developed-by: Mimi Zohar Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar

evm: Use the metadata inode to calculate metadata hash

2024-04-09T21:14:57Z

Changes to file attributes (mode bits, uid, gid) on the lower layer are not taken into account when d_backing_inode() is used when a file is accessed on the overlay layer and this file has not yet been copied up. This is because d_backing_inode() does not return the real inode of the lower layer but instead returns the backing inode which in this case holds wrong file attributes. Further, when CONFIG_OVERLAY_FS_METACOPY is enabled and a copy-up is triggered due to file metadata changes, then the metadata are held by the backing inode while the data are still held by the real inode. Therefore, use d_inode(d_real(dentry, D_REAL_METADATA)) to get to the file's metadata inode and use it to calculate the metadata hash with. Co-developed-by: Mimi Zohar Signed-off-by: Stefan Berger Acked-by: Amir Goldstein Signed-off-by: Mimi Zohar

evm: Make it independent from 'integrity' LSM

2024-02-16T04:43:47Z

Define a new structure for EVM-specific metadata, called evm_iint_cache, and embed it in the inode security blob. Introduce evm_iint_inode() to retrieve metadata, and register evm_inode_alloc_security() for the inode_alloc_security LSM hook, to initialize the structure (before splitting metadata, this task was done by iint_init_always()). Keep the non-NULL checks after calling evm_iint_inode() except in evm_inode_alloc_security(), to take into account inodes for which security_inode_alloc() was not called. When using shared metadata, obtaining a NULL pointer from integrity_iint_find() meant that the file wasn't in the IMA policy. Now, because IMA and EVM use disjoint metadata, the EVM status has to be stored for every inode regardless of the IMA policy. Given that from now on EVM relies on its own metadata, remove the iint parameter from evm_verifyxattr(). Also, directly retrieve the iint in evm_verify_hmac(), called by both evm_verifyxattr() and evm_verify_current_integrity(), since now there is no performance penalty in retrieving EVM metadata (constant time). Replicate the management of the IMA_NEW_FILE flag, by introducing evm_post_path_mknod() and evm_file_release() to respectively set and clear the newly introduced flag EVM_NEW_FILE, at the same time IMA does. Like for IMA, select CONFIG_SECURITY_PATH when EVM is enabled, to ensure that files are marked as new. Unlike ima_post_path_mknod(), evm_post_path_mknod() cannot check if a file must be appraised. Thus, it marks all affected files. Also, it does not clear EVM_NEW_FILE depending on i_version, but that is not a problem because IMA_NEW_FILE is always cleared when set in ima_check_last_writer(). Move the EVM-specific flag EVM_IMMUTABLE_DIGSIG to security/integrity/evm/evm.h, since that definition is now unnecessary in the common integrity layer. Finally, switch to the LSM reservation mechanism for the EVM xattr, and consequently decrement by one the number of xattrs to allocate in security_inode_init_security(). Signed-off-by: Roberto Sassu Reviewed-by: Casey Schaufler Reviewed-by: Stefan Berger Reviewed-by: Mimi Zohar Acked-by: Mimi Zohar Signed-off-by: Paul Moore

evm: Support multiple LSMs providing an xattr

2023-07-10T17:59:39Z

Currently, evm_inode_init_security() processes a single LSM xattr from the array passed by security_inode_init_security(), and calculates the HMAC on it and other inode metadata. As the LSM infrastructure now can pass to EVM an array with multiple xattrs, scan them until the terminator (xattr name NULL), and calculate the HMAC on all of them. Also, double check that the xattrs array terminator is the first non-filled slot (obtained with lsm_get_xattr_slot()). Consumers of the xattrs array, such as the initxattrs() callbacks, rely on the terminator. Finally, change the name of the lsm_xattr parameter of evm_init_hmac() to xattrs, to reflect the new type of information passed. Signed-off-by: Roberto Sassu Reviewed-by: Mimi Zohar Acked-by: Mimi Zohar Signed-off-by: Paul Moore

evm: Fix build warnings

2023-06-06T12:51:11Z

Fix build warnings (function parameters description) for evm_read_protected_xattrs(), evm_set_key() and evm_verifyxattr(). Fixes: 7626676320f3 ("evm: provide a function to set the EVM key from the kernel") # v4.5+ Fixes: 8314b6732ae4 ("ima: Define new template fields xattrnames, xattrlengths and xattrvalues") # v5.14+ Fixes: 2960e6cb5f7c ("evm: additional parameter to pass integrity cache entry 'iint'") # v3.2+ Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar

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

2023-02-22T20:36:25Z

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

evm: call dump_security_xattr() in all cases to remove code duplication

2023-01-31T17:47:16Z

Currently dump_security_xattr() is used to dump security xattr value which is larger than 64 bytes, otherwise, pr_debug() is used. In order to remove code duplication, refactor dump_security_xattr() and call it in all cases. Signed-off-by: Xiu Jianfeng Signed-off-by: Mimi Zohar

fs: port xattr to mnt_idmap

2023-01-19T08:24:28Z

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)