[moderation] [tomoyo?] general protection fault in tomoyo_check_acl (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e2a936998ab2 Merge tag 'drm-fixes-2026-07-25' of https://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=120da6b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c05be6c9b0d36cb9
dashboard link: https://syzkaller.appspot.com/bug?extid=db7c0aeacaad126fe070
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [jmo...@namei.org linux-...@vger.kernel.org linux-secu...@vger.kernel.org pa...@paul-moore.com penguin...@I-love.SAKURA.ne.jp se...@hallyn.com take...@nttdata.co.jp tomoyo-...@lists.sourceforge.net]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-e2a93699.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b2992c347575/vmlinux-e2a93699.xz
kernel image: https://storage.googleapis.com/syzbot-assets/622a291c39d7/bzImage-e2a93699.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+db7c0a...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xee000d10066c79f3: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x700088803363cf98-0x700088803363cf9f]
CPU: 0 UID: 0 PID: 4698 Comm: udevd 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:tomoyo_check_acl+0xc0/0x400 security/tomoyo/domain.c:173
Code: 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 02 00 00 4c 8b 75 00 49 39 ee 0f 84 e6 01 00 00 4d 8d 7e 18 4c 89 f8 48 c1 e8 03 <0f> b6 04 18 84 c0 0f 85 09 01 00 00 45 0f b6 3f 31 ff 44 89 fe e8
RSP: 0018:ffffc900021df690 EFLAGS: 00010206
RAX: 0e001110066c79f3 RBX: dffffc0000000000 RCX: 1ffff9200043befd
RDX: 0000000000000000 RSI: ffffffff848ab550 RDI: ffff88801f635317
RBP: ffff88801f635310 R08: ffff888000fb2540 R09: 0000000000000002
R10: 000000000000005c R11: 0000000000000000 R12: ffffc900021df7c8
R13: 0000000000000000 R14: 700088803363cf80 R15: 700088803363cf98
FS: 00007f78b97c9880(0000) GS:ffff88808c545000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000c16000 CR3: 000000001294e000 CR4: 0000000000352ef0
Call Trace:
<TASK>
tomoyo_path_permission+0x1a6/0x3b0 security/tomoyo/file.c:591
tomoyo_check_open_permission+0x2b2/0x470 security/tomoyo/file.c:782
security_file_open+0xa9/0x240 security/security.c:2739
do_dentry_open+0x4a0/0x1380 fs/open.c:924
vfs_open+0x3b/0x340 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x2e44/0x3830 fs/namei.c:4863
do_file_open+0x23e/0x4a0 fs/namei.c:4892
do_sys_openat2+0x115/0x200 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f78b90a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff46bb92c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f78b97c9880 RCX: 00007f78b90a7407
RDX: 0000000000080000 RSI: 00007fff46bb9440 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005606e757f7f5
R13: 00005606e757f7f5 R14: 0000000000000001 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:tomoyo_check_acl+0xc0/0x400 security/tomoyo/domain.c:173
Code: 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 02 00 00 4c 8b 75 00 49 39 ee 0f 84 e6 01 00 00 4d 8d 7e 18 4c 89 f8 48 c1 e8 03 <0f> b6 04 18 84 c0 0f 85 09 01 00 00 45 0f b6 3f 31 ff 44 89 fe e8
RSP: 0018:ffffc900021df690 EFLAGS: 00010206
RAX: 0e001110066c79f3 RBX: dffffc0000000000 RCX: 1ffff9200043befd
RDX: 0000000000000000 RSI: ffffffff848ab550 RDI: ffff88801f635317
RBP: ffff88801f635310 R08: ffff888000fb2540 R09: 0000000000000002
R10: 000000000000005c R11: 0000000000000000 R12: ffffc900021df7c8
R13: 0000000000000000 R14: 700088803363cf80 R15: 700088803363cf98
FS: 00007f78b97c9880(0000) GS:ffff88808c545000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000c16000 CR3: 000000001294e000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 89 f8 mov %edi,%eax
2: 48 c1 e8 03 shr $0x3,%rax
6: 0f b6 04 18 movzbl (%rax,%rbx,1),%eax
a: 84 c0 test %al,%al
c: 0f 85 bd 02 00 00 jne 0x2cf
12: 4c 8b 75 00 mov 0x0(%rbp),%r14
16: 49 39 ee cmp %rbp,%r14
19: 0f 84 e6 01 00 00 je 0x205
1f: 4d 8d 7e 18 lea 0x18(%r14),%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 0f b6 04 18 movzbl (%rax,%rbx,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 0f 85 09 01 00 00 jne 0x13f
36: 45 0f b6 3f movzbl (%r15),%r15d
3a: 31 ff xor %edi,%edi
3c: 44 89 fe mov %r15d,%esi
3f: e8 .byte 0xe8


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