kernel/linux.git/security/apparmor/policy.c, branch v7.0.12

apparmor: fix race on rawdata dereference

2026-03-09T23:05:44+00:00

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

apparmor: fix unprivileged local user can do privileged policy management

2026-03-09T23:05:43+00:00

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

apparmor: Fix double free of ns_name in aa_replace_profiles()

2026-03-09T23:05:43+00:00

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

apparmor: replace recursive profile removal with iterative approach

2026-03-09T23:05:42+00:00

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

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

apparmor: guard against free routines being called with a NULL

2026-01-29T09:27:54+00:00

aa_free_data() and free_attachment() don't guard against having a NULL parameter passed to them. Fix this. Reviewed-by: Ryan Lee Signed-off-by: John Johansen

apparmor: add support loading per permission tagging

2026-01-29T09:27:47+00:00

Add support for the per permission tag index for a given permission set. This will be used by both meta-data tagging, to allow annotating accept states with context and debug information. As well as by rule tainting and triggers to specify the taint or trigger to be applied. Since these are low frequency ancillary data items they are stored in a tighter packed format to that allows for sharing and reuse of the strings between permissions and accept states. Reducing the amount of kernel memory use at the cost of having to go through a couple if index based indirections. The tags are just strings that has no meaning with out context. When used as meta-data for auditing and debugging its entirely information for userspace, but triggers, and tainting can be used to affect the domain. However they all exist in the same packed data set and can be shared between different uses. Signed-off-by: John Johansen

apparmor: make str table more generic and be able to have multiple entries

2026-01-22T12:56:39+00:00

The strtable is currently limited to a single entry string on unpack even though domain has the concept of multiple entries within it. Make this a reality as it will be used for tags and more advanced domain transitions. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen

apparmor: replace sprintf with snprintf in aa_new_learning_profile

2026-01-16T18:46:54+00:00

Replace unbounded sprintf() calls with snprintf() to prevent potential buffer overflows in aa_new_learning_profile(). While the current code works correctly, snprintf() is safer and follows secure coding best practices. No functional changes. Signed-off-by: Thorsten Blum Signed-off-by: John Johansen

apparmor: fix: oops when trying to free null ruleset

2025-08-04T08:14:56+00:00

profile allocation is wrongly setting the number of entries on the rules vector before any ruleset is assigned. If profile allocation fails between ruleset allocation and assigning the first ruleset, free_ruleset() will be called with a null pointer resulting in an oops. [ 107.350226] kernel BUG at mm/slub.c:545! [ 107.350912] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 107.351447] CPU: 1 UID: 0 PID: 27 Comm: ksoftirqd/1 Not tainted 6.14.6-hwe-rlee287-dev+ #5 [ 107.353279] Hardware name:[ 107.350218] -QE-----------[ cutMU here ]--------- Ub--- [ 107.3502untu26] kernel BUG a 24t mm/slub.c:545.!04 P [ 107.350912]C ( Oops: invalid oi4pcode: 0000 [#1]40 PREEMPT SMP NOPFXTI + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 107.356054] RIP: 0010:__slab_free+0x152/0x340 [ 107.356444] Code: 00 4c 89 ff e8 0f ac df 00 48 8b 14 24 48 8b 4c 24 20 48 89 44 24 08 48 8b 03 48 c1 e8 09 83 e0 01 88 44 24 13 e9 71 ff ff ff <0f> 0b 41 f7 44 24 08 87 04 00 00 75 b2 eb a8 41 f7 44 24 08 87 04 [ 107.357856] RSP: 0018:ffffad4a800fbbb0 EFLAGS: 00010246 [ 107.358937] RAX: ffff97ebc2a88e70 RBX: ffffd759400aa200 RCX: 0000000000800074 [ 107.359976] RDX: ffff97ebc2a88e60 RSI: ffffd759400aa200 RDI: ffffad4a800fbc20 [ 107.360600] RBP: ffffad4a800fbc50 R08: 0000000000000001 R09: ffffffff86f02cf2 [ 107.361254] R10: 0000000000000000 R11: 0000000000000000 R12: ffff97ecc0049400 [ 107.361934] R13: ffff97ebc2a88e60 R14: ffff97ecc0049400 R15: 0000000000000000 [ 107.362597] FS: 0000000000000000(0000) GS:ffff97ecfb200000(0000) knlGS:0000000000000000 [ 107.363332] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 107.363784] CR2: 000061c9545ac000 CR3: 0000000047aa6000 CR4: 0000000000750ef0 [ 107.364331] PKRU: 55555554 [ 107.364545] Call Trace: [ 107.364761] [ 107.364931] ? local_clock+0x15/0x30 [ 107.365219] ? srso_alias_return_thunk+0x5/0xfbef5 [ 107.365593] ? kfree_sensitive+0x32/0x70 [ 107.365900] kfree+0x29d/0x3a0 [ 107.366144] ? srso_alias_return_thunk+0x5/0xfbef5 [ 107.366510] ? local_clock_noinstr+0xe/0xd0 [ 107.366841] ? srso_alias_return_thunk+0x5/0xfbef5 [ 107.367209] kfree_sensitive+0x32/0x70 [ 107.367502] aa_free_profile.part.0+0xa2/0x400 [ 107.367850] ? rcu_do_batch+0x1e6/0x5e0 [ 107.368148] aa_free_profile+0x23/0x60 [ 107.368438] label_free_switch+0x4c/0x80 [ 107.368751] label_free_rcu+0x1c/0x50 [ 107.369038] rcu_do_batch+0x1e8/0x5e0 [ 107.369324] ? rcu_do_batch+0x157/0x5e0 [ 107.369626] rcu_core+0x1b0/0x2f0 [ 107.369888] rcu_core_si+0xe/0x20 [ 107.370156] handle_softirqs+0x9b/0x3d0 [ 107.370460] ? smpboot_thread_fn+0x26/0x210 [ 107.370790] run_ksoftirqd+0x3a/0x70 [ 107.371070] smpboot_thread_fn+0xf9/0x210 [ 107.371383] ? __pfx_smpboot_thread_fn+0x10/0x10 [ 107.371746] kthread+0x10d/0x280 [ 107.372010] ? __pfx_kthread+0x10/0x10 [ 107.372310] ret_from_fork+0x44/0x70 [ 107.372655] ? __pfx_kthread+0x10/0x10 [ 107.372974] ret_from_fork_asm+0x1a/0x30 [ 107.373316] [ 107.373505] Modules linked in: af_packet_diag mptcp_diag tcp_diag udp_diag raw_diag inet_diag snd_seq_dummy snd_hrtimer snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd soundcore qrtr binfmt_misc intel_rapl_msr intel_rapl_common kvm_amd ccp kvm irqbypass polyval_clmulni polyval_generic ghash_clmulni_intel sha256_ssse3 sha1_ssse3 aesni_intel crypto_simd cryptd i2c_piix4 i2c_smbus input_leds joydev sch_fq_codel msr parport_pc ppdev lp parport efi_pstore nfnetlink vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock vmw_vmci dmi_sysfs qemu_fw_cfg ip_tables x_tables autofs4 hid_generic usbhid hid psmouse serio_raw floppy bochs pata_acpi [ 107.379086] ---[ end trace 0000000000000000 ]--- Don't set the count until a ruleset is actually allocated and guard against free_ruleset() being called with a null pointer. Reported-by: Ryan Lee Fixes: 217af7e2f4de ("apparmor: refactor profile rules and attachments") Signed-off-by: John Johansen