linux.git/security/apparmor/lib.c, branch v7.3-rc2

apparmor: policy_int make sure list heads are initialized before fail path

2026-08-26T07:03:13+00:00

If profile create fails before policy_init is complete the list heads
are not properly initialized causing profile_free() sanity checks to
trigger the following splat.

AppArmor WARN aa_policy_destroy: (((!list_empty(&policy->profiles) && (&policy->profiles)->prev != ((void *) 0x122 + (0xdead000000000000UL))))):
WARNING: security/apparmor/lib.c:509 at aa_policy_destroy+0x164/0x1b0 security/apparmor/lib.c:509, CPU#0: syz.0.17/5541
Modules linked in:
CPU: 0 UID: 0 PID: 5541 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:aa_policy_destroy+0x16b/0x1b0 security/apparmor/lib.c:509
Code: 85 ed 7e 4d e8 96 bc 37 fd 5b 41 5c 41 5e 41 5f 5d e9 19 27 4e 07 cc e8 83 bc 37 fd 48 8d 3d 0c f0 d3 0b 48 c7 c6 a4 eb 38 8e <67> 48 0f b9 3a e9 04 ff ff ff e8 66 bc 37 fd 48 8d 3d ff ef d3 0b
RSP: 0018:ffffc9000345eaa0 EFLAGS: 00010293
RAX: ffffffff848f530d RBX: ffff88803f734800 RCX: ffff88801af2a580
RDX: 0000000000000000 RSI: ffffffff8e38eba4 RDI: ffffffff90634320
RBP: 0000000000000000 R08: 0000000000000cc0 R09: 00000000ffffffff
R10: dffffc0000000000 R11: fffffbfff1d95913 R12: dead000000000122
R13: ffff88803f734800 R14: ffff88803f734828 R15: dffffc0000000000
FS:  00007f5f6a1836c0(0000) GS:ffff88808c519000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d02407b048 CR3: 0000000012aa9000 CR4: 0000000000352ef0
Call Trace:
 
 aa_free_profile+0x9d/0x9f0 security/apparmor/policy.c:334
 aa_alloc_profile+0x1e4/0x3e0 security/apparmor/policy.c:416
 unpack_profile security/apparmor/policy_unpack.c:1153 [inline]
 aa_unpack+0x17db/0x7430 security/apparmor/policy_unpack.c:1748
 aa_replace_profiles+0x226/0x2a20 security/apparmor/policy.c:1183
 policy_update+0x234/0x4a0 security/apparmor/apparmorfs.c:505
 profile_load+0x1cb/0x320 security/apparmor/apparmorfs.c:522
 vfs_write+0x296/0xba0 fs/read_write.c:685
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f6939e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5f6a183028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f69625fa0 RCX: 00007f5f6939e0d9
RDX: 0000000000000041 RSI: 0000200000000400 RDI: 0000000000000003
RBP: 00007f5f6a183090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5f69626038 R14: 00007f5f69625fa0 R15: 00007ffe23725c18

Reported-by: syzbot+faed97c4ed43bfe7fee5@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=faed97c4ed43bfe7fee5
Fixes: fe6bb31f590c9 ("apparmor: split out shared policy_XXX fns to lib")
Signed-off-by: John Johansen

apparmor: constify aa_profile parameters on read-only compute paths

2026-08-11T05:49:43+00:00

A number of functions take a struct aa_profile * argument that is only
ever read from: they compute DFA matches or apply the profile's mode
flags without modifying the profile, taking a reference on it, or
touching its embedded label. Mark those parameters const struct
aa_profile * to document intent and let the compiler enforce it.

The converted functions are the permission "compute" path plus a few
pure readers:
  - aa_apply_modes_to_perms(), aa_profile_match_label()
  - AUDIT_MODE()
  - aa_label_match() and its match_component()/label_compound_match()/
    label_components_match() helpers (label.c)
  - match_component()/label_compound_match()/label_components_match()/
    label_match()/change_profile_perms()/aa_xattrs_match() (domain.c)
  - match_iface()/match_addr_iface()/match_addr_iface_label()/
    skb_match_to_sk()/skb_match_to_cmd() (af_inet.c)
  - aa_profile_capget(), path_flags(), profile_query_cb()

The remaining aa_profile * parameters cannot be made const: the audit
path stores &profile->label into the owned, refcounted
apparmor_audit_data.subj_label/peer fields, and the domain/lifecycle
paths take references on the profile's embedded label
(aa_get_label()/aa_get_newest_label()/aa_get_profile()) or write
profile fields.

No functional change.

Signed-off-by: John Johansen 
Assisted-by: Claude:claude-opus-4.8

apparmor: constify aa_perms parameters that are read-only

2026-08-11T05:49:42+00:00

Several functions take a struct aa_perms * argument that is only ever
read from and never modified through the pointer. Mark those parameters
const struct aa_perms * to document intent and let the compiler enforce
that the permission set is not mutated.

The converted functions are:
  - aa_check_perms()
  - aa_do_perms()
  - do_perms() (af_inet)
  - match_label() (af_unix)
  - verify_perm()
  - aa_perms_accum() / aa_perms_accum_raw() (@addend only)

No functional change.

Signed-off-by: John Johansen 
Assisted-by: Claude:claude-opus-4.8

apparmor: refactory mount to use check_perms

2026-08-11T05:49:42+00:00

Move the mount permissions check to use the common backend
aa_check_perms() to check permissions. This will make it so caching,
audit, complain, logic can be handled consistently in a single place.

Signed-off-by: John Johansen

apparmor: add audit mode to provide a mechanism to silence complain messages

2026-08-11T05:49:42+00:00

Complain messages can be very noisy and fill the logs quickly. Allow
complain (allow) messages to be silenced separate from denied
messages.

Signed-off-by: John Johansen

apparmor: mark static tables and structs as read only

2026-08-11T05:49:42+00:00

static tables, and structs that are initialized as part of their
data section or during init should be read only to protect against
accidental or malicous changes.

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: 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/strcpy with scnprintf/strscpy in aa_policy_init

2026-01-18T14:52:58+00:00

strcpy() is deprecated and sprintf() does not perform bounds checking
either. Although an overflow is unlikely, it's better to proactively
avoid it by using the safer strscpy() and scnprintf(), respectively.

Additionally, unify memory allocation for 'hname' to simplify and
improve aa_policy_init().

Closes: https://github.com/KSPP/linux/issues/88
Reviewed-by: Serge Hallyn 
Signed-off-by: Thorsten Blum 
Signed-off-by: John Johansen