linux.git/security/apparmor/path.c, branch v7.1-rc2 Linux kernel source tree apparmor: Fix string overrun due to missing termination 2026-04-23T03:09:05+00:00 Daniel J Blueman daniel@quora.org 2026-03-27T11:58:32+00:00 828bf7929bedcb79b560b5b4e44f22abee07d31b When booting Ubuntu 26.04 with Linux 7.0-rc4 on an ARM64 Qualcomm Snapdragon X1 we see a string buffer overrun: BUG: KASAN: slab-out-of-bounds in aa_dfa_match (security/apparmor/match.c:535) Read of size 1 at addr ffff0008901cc000 by task snap-update-ns/2120 CPU: 5 UID: 60578 PID: 2120 Comm: snap-update-ns Not tainted 7.0.0-rc4+ #22 PREEMPTLAZY Hardware name: LENOVO 83ED/LNVNB161216, BIOS NHCN60WW 09/11/2025 Call trace: show_stack (arch/arm64/kernel/stacktrace.c:501) (C) dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:379 mm/kasan/report.c:482) kasan_report (mm/kasan/report.c:597) __asan_report_load1_noabort (mm/kasan/report_generic.c:378) aa_dfa_match (security/apparmor/match.c:535) match_mnt_path_str (security/apparmor/mount.c:244 security/apparmor/mount.c:336) match_mnt (security/apparmor/mount.c:371) aa_bind_mount (security/apparmor/mount.c:447 (discriminator 4)) apparmor_sb_mount (security/apparmor/lsm.c:719 (discriminator 1)) security_sb_mount (security/security.c:1062 (discriminator 31)) path_mount (fs/namespace.c:4101) __arm64_sys_mount (fs/namespace.c:4172 fs/namespace.c:4361 fs/namespace.c:4338 fs/namespace.c:4338) invoke_syscall.constprop.0 (arch/arm64/kernel/syscall.c:35 arch/arm64/kernel/syscall.c:49) el0_svc_common.constprop.0 (./include/linux/thread_info.h:142 (discriminator 2) arch/arm64/kernel/syscall.c:140 (discriminator 2)) do_el0_svc (arch/arm64/kernel/syscall.c:152) el0_svc (arch/arm64/kernel/entry-common.c:80 arch/arm64/kernel/entry-common.c:725) el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:744) el0t_64_sync (arch/arm64/kernel/entry.S:596) Allocated by task 2120: kasan_save_stack (mm/kasan/common.c:58) kasan_save_track (./arch/arm64/include/asm/current.h:19 mm/kasan/common.c:70 mm/kasan/common.c:79) kasan_save_alloc_info (mm/kasan/generic.c:571) __kasan_kmalloc (mm/kasan/common.c:419) __kmalloc_noprof (./include/linux/kasan.h:263 mm/slub.c:5260 mm/slub.c:5272) aa_get_buffer (security/apparmor/lsm.c:2201) aa_bind_mount (security/apparmor/mount.c:442) apparmor_sb_mount (security/apparmor/lsm.c:719 (discriminator 1)) security_sb_mount (security/security.c:1062 (discriminator 31)) path_mount (fs/namespace.c:4101) __arm64_sys_mount (fs/namespace.c:4172 fs/namespace.c:4361 fs/namespace.c:4338 fs/namespace.c:4338) invoke_syscall.constprop.0 (arch/arm64/kernel/syscall.c:35 arch/arm64/kernel/syscall.c:49) el0_svc_common.constprop.0 (./include/linux/thread_info.h:142 (discriminator 2) arch/arm64/kernel/syscall.c:140 (discriminator 2)) do_el0_svc (arch/arm64/kernel/syscall.c:152) el0_svc (arch/arm64/kernel/entry-common.c:80 arch/arm64/kernel/entry-common.c:725) el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:744) el0t_64_sync (arch/arm64/kernel/entry.S:596) The buggy address belongs to the object at ffff0008901ca000 which belongs to the cache kmalloc-rnd-06-8k of size 8192 The buggy address is located 0 bytes to the right of allocated 8192-byte region [ffff0008901ca000, ffff0008901cc000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9101c8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:-1 pincount:0 flags: 0x8000000000000040(head|zone=2) page_type: f5(slab) raw: 8000000000000040 ffff000800016c40 fffffdffe2d14e10 ffff000800015c70 raw: 0000000000000000 0000000800010001 00000000f5000000 0000000000000000 head: 8000000000000040 ffff000800016c40 fffffdffe2d14e10 ffff000800015c70 head: 0000000000000000 0000000800010001 00000000f5000000 0000000000000000 head: 8000000000000003 fffffdffe2407201 fffffdffffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0008901cbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0008901cbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0008901cc000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff0008901cc080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0008901cc100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc This was introduced by previous incorrect conversion from strcpy(). Fix it by adding the missing terminator. Cc: stable@vger.kernel.org Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com> Signed-off-by: Daniel J Blueman <daniel@quora.org> Fixes: 93d4dbdc8da0 ("apparmor: Replace deprecated strcpy in d_namespace_path") Signed-off-by: John Johansen <john.johansen@canonical.com> 
When booting Ubuntu 26.04 with Linux 7.0-rc4 on an ARM64 Qualcomm
Snapdragon X1 we see a string buffer overrun:

BUG: KASAN: slab-out-of-bounds in aa_dfa_match (security/apparmor/match.c:535)
Read of size 1 at addr ffff0008901cc000 by task snap-update-ns/2120

CPU: 5 UID: 60578 PID: 2120 Comm: snap-update-ns Not tainted 7.0.0-rc4+ #22 PREEMPTLAZY
Hardware name: LENOVO 83ED/LNVNB161216, BIOS NHCN60WW 09/11/2025
Call trace:
show_stack (arch/arm64/kernel/stacktrace.c:501) (C)
dump_stack_lvl (lib/dump_stack.c:122)
print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:597)
__asan_report_load1_noabort (mm/kasan/report_generic.c:378)
aa_dfa_match (security/apparmor/match.c:535)
match_mnt_path_str (security/apparmor/mount.c:244 security/apparmor/mount.c:336)
match_mnt (security/apparmor/mount.c:371)
aa_bind_mount (security/apparmor/mount.c:447 (discriminator 4))
apparmor_sb_mount (security/apparmor/lsm.c:719 (discriminator 1))
security_sb_mount (security/security.c:1062 (discriminator 31))
path_mount (fs/namespace.c:4101)
__arm64_sys_mount (fs/namespace.c:4172 fs/namespace.c:4361 fs/namespace.c:4338 fs/namespace.c:4338)
invoke_syscall.constprop.0 (arch/arm64/kernel/syscall.c:35 arch/arm64/kernel/syscall.c:49)
el0_svc_common.constprop.0 (./include/linux/thread_info.h:142 (discriminator 2) arch/arm64/kernel/syscall.c:140 (discriminator 2))
do_el0_svc (arch/arm64/kernel/syscall.c:152)
el0_svc (arch/arm64/kernel/entry-common.c:80 arch/arm64/kernel/entry-common.c:725)
el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:744)
el0t_64_sync (arch/arm64/kernel/entry.S:596)

Allocated by task 2120:
kasan_save_stack (mm/kasan/common.c:58)
kasan_save_track (./arch/arm64/include/asm/current.h:19 mm/kasan/common.c:70 mm/kasan/common.c:79)
kasan_save_alloc_info (mm/kasan/generic.c:571)
__kasan_kmalloc (mm/kasan/common.c:419)
__kmalloc_noprof (./include/linux/kasan.h:263 mm/slub.c:5260 mm/slub.c:5272)
aa_get_buffer (security/apparmor/lsm.c:2201)
aa_bind_mount (security/apparmor/mount.c:442)
apparmor_sb_mount (security/apparmor/lsm.c:719 (discriminator 1))
security_sb_mount (security/security.c:1062 (discriminator 31))
path_mount (fs/namespace.c:4101)
__arm64_sys_mount (fs/namespace.c:4172 fs/namespace.c:4361 fs/namespace.c:4338 fs/namespace.c:4338)
invoke_syscall.constprop.0 (arch/arm64/kernel/syscall.c:35 arch/arm64/kernel/syscall.c:49)
el0_svc_common.constprop.0 (./include/linux/thread_info.h:142 (discriminator 2) arch/arm64/kernel/syscall.c:140 (discriminator 2))
do_el0_svc (arch/arm64/kernel/syscall.c:152)
el0_svc (arch/arm64/kernel/entry-common.c:80 arch/arm64/kernel/entry-common.c:725)
el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:744)
el0t_64_sync (arch/arm64/kernel/entry.S:596)

The buggy address belongs to the object at ffff0008901ca000
which belongs to the cache kmalloc-rnd-06-8k of size 8192
The buggy address is located 0 bytes to the right of
allocated 8192-byte region [ffff0008901ca000, ffff0008901cc000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9101c8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:-1 pincount:0
flags: 0x8000000000000040(head|zone=2)
page_type: f5(slab)
raw: 8000000000000040 ffff000800016c40 fffffdffe2d14e10 ffff000800015c70
raw: 0000000000000000 0000000800010001 00000000f5000000 0000000000000000
head: 8000000000000040 ffff000800016c40 fffffdffe2d14e10 ffff000800015c70
head: 0000000000000000 0000000800010001 00000000f5000000 0000000000000000
head: 8000000000000003 fffffdffe2407201 fffffdffffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff0008901cbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff0008901cbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0008901cc000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff0008901cc080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0008901cc100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

This was introduced by previous incorrect conversion from strcpy(). Fix it
by adding the missing terminator.

Cc: stable@vger.kernel.org
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: Daniel J Blueman <daniel@quora.org>
Fixes: 93d4dbdc8da0 ("apparmor: Replace deprecated strcpy in d_namespace_path")
Signed-off-by: John Johansen <john.johansen@canonical.com>
apparmor: Replace deprecated strcpy in d_namespace_path 2026-01-18T14:53:18+00:00 Thorsten Blum thorsten.blum@linux.dev 2025-11-06T14:51:38+00:00 93d4dbdc8da0b8a3ba86f4a08868084f8da872e1 strcpy() is deprecated; replace it with a direct '/' assignment. The buffer is already NUL-terminated, so there is no need to copy an additional NUL terminator as strcpy() did. Update the comment and add the local variable 'is_root' for clarity. Closes: https://github.com/KSPP/linux/issues/88 Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: John Johansen <john.johansen@canonical.com> 
strcpy() is deprecated; replace it with a direct '/' assignment. The
buffer is already NUL-terminated, so there is no need to copy an
additional NUL terminator as strcpy() did.

Update the comment and add the local variable 'is_root' for clarity.

Closes: https://github.com/KSPP/linux/issues/88
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: John Johansen <john.johansen@canonical.com>
apparmor: Use IS_ERR_OR_NULL() helper function 2024-11-27T03:21:05+00:00 Hongbo Li lihongbo22@huawei.com 2024-08-28T12:26:18+00:00 c03093730616a0ce23b1f25f0c5a7f3f613ca94a Use the IS_ERR_OR_NULL() helper instead of open-coding a NULL and an error pointer checks to simplify the code and improve readability. Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: John Johansen <john.johansen@canonical.com> 
Use the IS_ERR_OR_NULL() helper instead of open-coding a
NULL and an error pointer checks to simplify the code and
improve readability.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
security: apparmor: delete repeated words in comments 2021-02-07T12:15:46+00:00 Randy Dunlap rdunlap@infradead.org 2020-08-07T16:50:55+00:00 4af7c863fc85ad756b7a978fe1096b80a855543c Drop repeated words in comments. {a, then, to} Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Seth Arnold <seth.arnold@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com> 
Drop repeated words in comments.
{a, then, to}

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
AppArmor: Remove semicolon 2020-01-18T23:36:58+00:00 Vasyl Gomonovych gomonovych@gmail.com 2019-07-26T13:32:10+00:00 e4f4e6ba5eaadb839d17cfe5235cff149a44b36a Remove unneeded semicolon Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com> 
Remove unneeded semicolon

Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05T15:37:17+00:00 Thomas Gleixner tglx@linutronix.de 2019-06-01T08:08:55+00:00 b886d83c5b621abc84ff9616f14c529be3f6b147 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
apparmor: Move path lookup to using preallocated buffers 2017-06-08T18:29:34+00:00 John Johansen john.johansen@canonical.com 2017-05-23T10:25:14+00:00 4227c333f65cddc6c2f048e5b67cfe796b9df9a6 Dynamically allocating buffers is problematic and is an extra layer that is a potntial point of failure and can slow down mediation. Change path lookup to use the preallocated per cpu buffers. Signed-off-by: John Johansen <john.johansen@canonical.com> 
Dynamically allocating buffers is problematic and is an extra layer
that is a potntial point of failure and can slow down mediation.
Change path lookup to use the preallocated per cpu buffers.

Signed-off-by: John Johansen <john.johansen@canonical.com>
apparmor: allow profiles to provide info to disconnected paths 2017-06-08T18:29:34+00:00 John Johansen john.johansen@canonical.com 2017-05-22T10:06:52+00:00 72c8a768641dc6ee8d1d9dcebd51bbec2817459b Signed-off-by: John Johansen <john.johansen@canonical.com> 
Signed-off-by: John Johansen <john.johansen@canonical.com>
apparmor: internal paths should be treated as disconnected 2016-07-12T15:43:10+00:00 John Johansen john.johansen@canonical.com 2014-07-25T11:02:10+00:00 bd35db8b8ca6e27fc17a9057ef78e1ddfc0de351 Internal mounts are not mounted anywhere and as such should be treated as disconnected paths. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com> 
Internal mounts are not mounted anywhere and as such should be treated
as disconnected paths.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
apparmor: fix disconnected bind mnts reconnection 2016-07-12T15:43:10+00:00 John Johansen john.johansen@canonical.com 2014-07-25T11:02:08+00:00 f2e561d190da7ff5ee265fa460e2d7f753dddfda Bind mounts can fail to be properly reconnected when PATH_CONNECT is specified. Ensure that when PATH_CONNECT is specified the path has a root. BugLink: http://bugs.launchpad.net/bugs/1319984 Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com> 
Bind mounts can fail to be properly reconnected when PATH_CONNECT is
specified. Ensure that when PATH_CONNECT is specified the path has
a root.

BugLink: http://bugs.launchpad.net/bugs/1319984

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>