kernel/git/stable/linux.git/security/apparmor, branch linux-6.16.y

apparmor: Fix 8-byte alignment for initial dfa blob streams

2025-08-28T14:34:16+00:00

commit c567de2c4f5fe6e079672e074e1bc6122bf7e444 upstream. The dfa blob stream for the aa_dfa_unpack() function is expected to be aligned on a 8 byte boundary. The static nulldfa_src[] and stacksplitdfa_src[] arrays store the initial apparmor dfa blob streams, but since they are declared as an array-of-chars the compiler and linker will only ensure a "char" (1-byte) alignment. Add an __aligned(8) annotation to the arrays to tell the linker to always align them on a 8-byte boundary. This avoids runtime warnings at startup on alignment-sensitive platforms like parisc such as: Kernel: unaligned access to 0x7f2a584a in aa_dfa_unpack+0x124/0x788 (iir 0xca0109f) Kernel: unaligned access to 0x7f2a584e in aa_dfa_unpack+0x210/0x788 (iir 0xca8109c) Kernel: unaligned access to 0x7f2a586a in aa_dfa_unpack+0x278/0x788 (iir 0xcb01090) Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Fixes: 98b824ff8984 ("apparmor: refcount the pdb") Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix x_table_lookup when stacking is not the first entry

2025-08-20T16:41:29+00:00

[ Upstream commit a9eb185be84e998aa9a99c7760534ccc06216705 ] x_table_lookup currently does stacking during label_parse() if the target specifies a stack but its only caller ensures that it will never be used with stacking. Refactor to slightly simplify the code in x_to_label(), this also fixes a long standing problem where x_to_labels check on stacking is only on the first element to the table option list, instead of the element that is found and used. Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: use the condition in AA_BUG_FMT even with debug disabled

2025-08-20T16:41:29+00:00

[ Upstream commit 67e370aa7f968f6a4f3573ed61a77b36d1b26475 ] This follows the established practice and fixes a build failure for me: security/apparmor/file.c: In function ‘__file_sock_perm’: security/apparmor/file.c:544:24: error: unused variable ‘sock’ [-Werror=unused-variable] 544 | struct socket *sock = (struct socket *) file->private_data; | ^~~~ Signed-off-by: Mateusz Guzik Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: shift ouid when mediating hard links in userns

2025-08-20T16:41:28+00:00

[ Upstream commit c5bf96d20fd787e4909b755de4705d52f3458836 ] When using AppArmor profiles inside an unprivileged container, the link operation observes an unshifted ouid. (tested with LXD and Incus) For example, root inside container and uid 1000000 outside, with `owner /root/link l,` profile entry for ln: /root$ touch chain && ln chain link ==> dmesg apparmor="DENIED" operation="link" class="file" namespace="root//lxd-feet_" profile="linkit" name="/root/link" pid=1655 comm="ln" requested_mask="l" denied_mask="l" fsuid=1000000 ouid=0 [<== should be 1000000] target="/root/chain" Fix by mapping inode uid of old_dentry in aa_path_link() rather than using it directly, similarly to how it's mapped in __file_path_perm() later in the file. Signed-off-by: Gabriel Totev Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: Fix unaligned memory accesses in KUnit test

2025-08-15T14:39:16+00:00

[ Upstream commit c68804199dd9d63868497a27b5da3c3cd15356db ] The testcase triggers some unnecessary unaligned memory accesses on the parisc architecture: Kernel: unaligned access to 0x12f28e27 in policy_unpack_test_init+0x180/0x374 (iir 0x0cdc1280) Kernel: unaligned access to 0x12f28e67 in policy_unpack_test_init+0x270/0x374 (iir 0x64dc00ce) Use the existing helper functions put_unaligned_le32() and put_unaligned_le16() to avoid such warnings on architectures which prefer aligned memory accesses. Signed-off-by: Helge Deller Fixes: 98c0cc48e27e ("apparmor: fix policy_unpack_test on big endian systems") Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: fix loop detection used in conflicting attachment resolution

2025-08-15T14:39:15+00:00

[ Upstream commit a88db916b8c77552f49f7d9f8744095ea01a268f ] Conflicting attachment resolution is based on the number of states traversed to reach an accepting state in the attachment DFA, accounting for DFA loops traversed during the matching process. However, the loop counting logic had multiple bugs: - The inc_wb_pos macro increments both position and length, but length is supposed to saturate upon hitting buffer capacity, instead of wrapping around. - If no revisited state is found when traversing the history, is_loop would still return true, as if there was a loop found the length of the history buffer, instead of returning false and signalling that no loop was found. As a result, the adjustment step of aa_dfa_leftmatch would sometimes produce negative counts with loop- free DFAs that traversed enough states. - The iteration in the is_loop for loop is supposed to stop before i = wb->len, so the conditional should be < instead of <=. This patch fixes the above bugs as well as the following nits: - The count and size fields in struct match_workbuf were not used, so they can be removed. - The history buffer in match_workbuf semantically stores aa_state_t and not unsigned ints, even if aa_state_t is currently unsigned int. - The local variables in is_loop are counters, and thus should be unsigned ints instead of aa_state_t's. Fixes: 21f606610502 ("apparmor: improve overlapping domain attachment resolution") Signed-off-by: Ryan Lee Co-developed-by: John Johansen Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: ensure WB_HISTORY_SIZE value is a power of 2

2025-08-15T14:39:15+00:00

[ Upstream commit 6c055e62560b958354625604293652753d82bcae ] WB_HISTORY_SIZE was defined to be a value not a power of 2, despite a comment in the declaration of struct match_workbuf stating it is and a modular arithmetic usage in the inc_wb_pos macro assuming that it is. Bump WB_HISTORY_SIZE's value up to 32 and add a BUILD_BUG_ON_NOT_POWER_OF_2 line to ensure that any future changes to the value of WB_HISTORY_SIZE respect this requirement. Fixes: 136db994852a ("apparmor: increase left match history buffer size") Signed-off-by: Ryan Lee Signed-off-by: John Johansen Signed-off-by: Sasha Levin

VFS: rename lookup_one_len family to lookup_noperm and remove permission check

2025-04-08T09:24:36+00:00

The lookup_one_len family of functions is (now) only used internally by a filesystem on itself either - in a context where permission checking is irrelevant such as by a virtual filesystem populating itself, or xfs accessing its ORPHANAGE or dquota accessing the quota file; or - in a context where a permission check (MAY_EXEC on the parent) has just been performed such as a network filesystem finding in "silly-rename" file in the same directory. This is also the context after the _parentat() functions where currently lookup_one_qstr_excl() is used. So the permission check is pointless. The name "one_len" is unhelpful in understanding the purpose of these functions and should be changed. Most of the callers pass the len as "strlen()" so using a qstr and QSTR() can simplify the code. This patch renames these functions (include lookup_positive_unlocked() which is part of the family despite the name) to have a name based on "lookup_noperm". They are changed to receive a 'struct qstr' instead of separate name and len. In a few cases the use of QSTR() results in a new call to strlen(). try_lookup_noperm() takes a pointer to a qstr instead of the whole qstr. This is consistent with d_hash_and_lookup() (which is nearly identical) and useful for lookup_noperm_unlocked(). The new lookup_noperm_common() doesn't take a qstr yet. That will be tidied up in a subsequent patch. Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250319031545.2999807-5-neil@brown.name Signed-off-by: Christian Brauner

Change inode_operations.mkdir to return struct dentry *

2025-02-27T19:00:17+00:00

Some filesystems, such as NFS, cifs, ceph, and fuse, do not have complete control of sequencing on the actual filesystem (e.g. on a different server) and may find that the inode created for a mkdir request already exists in the icache and dcache by the time the mkdir request returns. For example, if the filesystem is mounted twice the directory could be visible on the other mount before it is on the original mount, and a pair of name_to_handle_at(), open_by_handle_at() calls could instantiate the directory inode with an IS_ROOT() dentry before the first mkdir returns. This means that the dentry passed to ->mkdir() may not be the one that is associated with the inode after the ->mkdir() completes. Some callers need to interact with the inode after the ->mkdir completes and they currently need to perform a lookup in the (rare) case that the dentry is no longer hashed. This lookup-after-mkdir requires that the directory remains locked to avoid races. Planned future patches to lock the dentry rather than the directory will mean that this lookup cannot be performed atomically with the mkdir. To remove this barrier, this patch changes ->mkdir to return the resulting dentry if it is different from the one passed in. Possible returns are: NULL - the directory was created and no other dentry was used ERR_PTR() - an error occurred non-NULL - this other dentry was spliced in This patch only changes file-systems to return "ERR_PTR(err)" instead of "err" or equivalent transformations. Subsequent patches will make further changes to some file-systems to return a correct dentry. Not all filesystems reliably result in a positive hashed dentry: - NFS, cifs, hostfs will sometimes need to perform a lookup of the name to get inode information. Races could result in this returning something different. Note that this lookup is non-atomic which is what we are trying to avoid. Placing the lookup in filesystem code means it only happens when the filesystem has no other option. - kernfs and tracefs leave the dentry negative and the ->revalidate operation ensures that lookup will be called to correctly populate the dentry. This could be fixed but I don't think it is important to any of the users of vfs_mkdir() which look at the dentry. The recommendation to use d_drop();d_splice_alias() is ugly but fits with current practice. A planned future patch will change this. Reviewed-by: Jeff Layton Reviewed-by: Jan Kara Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de Signed-off-by: Christian Brauner

treewide: const qualify ctl_tables where applicable

2025-01-28T12:48:37+00:00

Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu Acked-by: Steven Rostedt (Google) # for kernel/trace/ Reviewed-by: Martin K. Petersen # SCSI Reviewed-by: Darrick J. Wong # xfs Acked-by: Jani Nikula Acked-by: Corey Minyard Acked-by: Wei Liu Acked-by: Thomas Gleixner Reviewed-by: Bill O'Donnell Acked-by: Baoquan He Acked-by: Ashutosh Dixit Acked-by: Anna Schumaker Signed-off-by: Joel Granados