kernel/linux.git/security/apparmor/policy.c, branch v6.12.80

apparmor: fix race on rawdata dereference

2026-03-13T16:20:48+00:00

commit a0b7091c4de45a7325c8780e6934a894f92ac86b upstream. There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put. Fixes: 5d5182cae401 ("apparmor: move to per loaddata files, instead of replicating in profiles") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Tested-by: Salvatore Bonaccorso Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix unprivileged local user can do privileged policy management

2026-03-13T16:20:48+00:00

commit 6601e13e82841879406bf9f369032656f441a425 upstream. An unprivileged local user can load, replace, and remove profiles by opening the apparmorfs interfaces, via a confused deputy attack, by passing the opened fd to a privileged process, and getting the privileged process to write to the interface. This does require a privileged target that can be manipulated to do the write for the unprivileged process, but once such access is achieved full policy management is possible and all the possible implications that implies: removing confinement, DoS of system or target applications by denying all execution, by-passing the unprivileged user namespace restriction, to exploiting kernel bugs for a local privilege escalation. The policy management interface can not have its permissions simply changed from 0666 to 0600 because non-root processes need to be able to load policy to different policy namespaces. Instead ensure the task writing the interface has privileges that are a subset of the task that opened the interface. This is already done via policy for confined processes, but unconfined can delegate access to the opened fd, by-passing the usual policy check. Fixes: b7fd2c0340eac ("apparmor: add per policy ns .load, .replace, .remove interface files") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: Fix double free of ns_name in aa_replace_profiles()

2026-03-13T16:20:48+00:00

commit 5df0c44e8f5f619d3beb871207aded7c78414502 upstream. if ns_name is NULL after 1071 error = aa_unpack(udata, &lh, &ns_name); and if ent->ns_name contains an ns_name in 1089 } else if (ent->ns_name) { then ns_name is assigned the ent->ns_name 1095 ns_name = ent->ns_name; however ent->ns_name is freed at 1262 aa_load_ent_free(ent); and then again when freeing ns_name at 1270 kfree(ns_name); Fix this by NULLing out ent->ns_name after it is transferred to ns_name Fixes: 145a0ef21c8e9 ("apparmor: fix blob compression when ns is forced on a policy load") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: replace recursive profile removal with iterative approach

2026-03-13T16:20:47+00:00

commit ab09264660f9de5d05d1ef4e225aa447c63a8747 upstream. The profile removal code uses recursion when removing nested profiles, which can lead to kernel stack exhaustion and system crashes. Reproducer: $ pf='a'; for ((i=0; i<1024; i++)); do echo -e "profile $pf { \n }" | apparmor_parser -K -a; pf="$pf//x"; done $ echo -n a > /sys/kernel/security/apparmor/.remove Replace the recursive __aa_profile_list_release() approach with an iterative approach in __remove_profile(). The function repeatedly finds and removes leaf profiles until the entire subtree is removed, maintaining the same removal semantic without recursion. Fixes: c88d4c7b049e ("AppArmor: core policy routines") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: Massimiliano Pellizzer Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: allocate xmatch for nullpdb inside aa_alloc_null

2025-01-23T16:23:05+00:00

commit 17d0d04f3c999e7784648bad70ce1766c3b49d69 upstream. attach->xmatch was not set when allocating a null profile, which is used in complain mode to allocate a learning profile. This was causing downstream failures in find_attach, which expected a valid xmatch but did not find one under a certain sequence of profile transitions in complain mode. This patch ensures the xmatch is set up properly for null profiles. Signed-off-by: Ryan Lee Signed-off-by: John Johansen Cc: Paul Kramme Signed-off-by: Greg Kroah-Hartman

apparmor: use kvfree_sensitive to free data->data

2024-05-10T15:32:35+00:00

Inside unpack_profile() data->data is allocated using kvmemdup() so it should be freed with the corresponding kvfree_sensitive(). Also add missing data->data release for rhashtable insertion failure path in unpack_profile(). Found by Linux Verification Center (linuxtesting.org). Fixes: e025be0f26d5 ("apparmor: support querying extended trusted helper extra data") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Signed-off-by: John Johansen

apparmor: free the allocated pdb objects

2024-01-03T19:48:02+00:00

policy_db objects are allocated with kzalloc() inside aa_alloc_pdb() and are not cleared in the corresponding aa_free_pdb() function causing leak: unreferenced object 0xffff88801f0a1400 (size 192): comm "apparmor_parser", pid 1247, jiffies 4295122827 (age 2306.399s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] __kmem_cache_alloc_node+0x1e2/0x2d0 [] kmalloc_trace+0x25/0xc0 [] aa_alloc_pdb+0x82/0x140 [] unpack_pdb+0xc7/0x2700 [] unpack_profile+0x450/0x4960 [] aa_unpack+0x309/0x15e0 [] aa_replace_profiles+0x213/0x33c0 [] policy_update+0x261/0x370 [] profile_replace+0x20e/0x2a0 [] vfs_write+0x2af/0xe00 [] ksys_write+0x126/0x250 [] do_syscall_64+0x46/0xf0 [] entry_SYSCALL_64_after_hwframe+0x6e/0x76 Free the pdbs inside aa_free_pdb(). While at it, rename the variable representing an aa_policydb object to make the function more unified with aa_pdb_free_kref() and aa_alloc_pdb(). Found by Linux Verification Center (linuxtesting.org). Fixes: 98b824ff8984 ("apparmor: refcount the pdb") Signed-off-by: Fedor Pchelkin Signed-off-by: John Johansen

apparmor: Fix some kernel-doc comments

2023-10-23T07:26:27+00:00

Fix some kernel-doc comments to silence the warnings: security/apparmor/policy.c:117: warning: Function parameter or member 'kref' not described in 'aa_pdb_free_kref' security/apparmor/policy.c:117: warning: Excess function parameter 'kr' description in 'aa_pdb_free_kref' security/apparmor/policy.c:882: warning: Function parameter or member 'subj_cred' not described in 'aa_may_manage_policy' Reported-by: Abaci Robot Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7037 Signed-off-by: Yang Li Signed-off-by: John Johansen

apparmor: allow restricting unprivileged change_profile

2023-10-18T22:48:44+00:00

unprivileged unconfined can use change_profile to alter the confinement set by the mac admin. Allow restricting unprivileged unconfined by still allowing change_profile but stacking the change against unconfined. This allows unconfined to still apply system policy but allows the task to enter the new confinement. If unprivileged unconfined is required a sysctl is provided to switch to the previous behavior. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen

apparmor: refcount the pdb

2023-10-18T22:30:47+00:00

With the move to permission tables the dfa is no longer a stand alone entity when used, needing a minimum of a permission table. However it still could be shared among different pdbs each using a different permission table. Instead of duping the permission table when sharing a pdb, add a refcount to the pdb so it can be easily shared. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen