syzbot
general protection fault in do_unlinkat
Status:
premoderation: reported C repro on 2025/07/15 16:32
Bug presence:
origin:downstream
[Documentation on labels]
Reported-by: syzbot+182816dea312c849adc5@syzkaller.appspotmail.com
First crash: 440d, last: 7d14h
▶
▼
Bug presence (3)
| Date |
Name |
Commit |
Repro |
Result |
| 2025/07/15 |
android16-6.12 (ToT) |
a11268a7e257 |
C
|
[report] general protection fault in do_unlinkat
|
| 2025/07/15 |
lts (merge base) |
e0e2f7824338 |
C
|
Didn't crash |
| 2025/07/15 |
upstream (ToT) |
155a3c003e55 |
C
|
Didn't crash |
▶
▼
Last patch testing requests (10)
Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 0 PID: 313 Comm: syz-executor419 Not tainted syzkaller #0 1e1e3c2f05ad74614550ef0faab423d4afe8f9f4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:419 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:465 [inline]
RIP: 0010:do_unlinkat+0x29c/0x5a0 fs/namei.c:4534
Code: 00 00 20 00 89 de e8 13 6a 98 ff 45 31 f6 81 fb 00 00 20 00 41 0f 95 c6 41 83 c6 eb 31 db e9 f4 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 04 02 00 00 41 8b 1f be 00 00 70 00 21
RSP: 0018:ffffc9000126fde0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88812e4b9300 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000126fee0 R08: ffff8881f6e50c47 R09: 1ffff1103edca188
R10: dffffc0000000000 R11: ffffed103edca189 R12: ffff88811fc48000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000008
FS: 00007ff1e5afe6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000a000 CR3: 00000001057b8000 CR4: 00000000003526b0
Call Trace:
<TASK>
__do_sys_unlinkat fs/namei.c:4584 [inline]
__se_sys_unlinkat fs/namei.c:4577 [inline]
__x64_sys_unlinkat+0xda/0xf0 fs/namei.c:4577
x64_sys_call+0x2974/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:264
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ff1e5b30e79
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff1e5afe218 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007ff1e5be1b68 RCX: 00007ff1e5b30e79
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 00007ff1e5be1b60 R08: 33203a6b63617473 R09: 33203a6b63617473
R10: 33203a6b63617473 R11: 0000000000000246 R12: 00007ff1e5baf41c
R13: 0000200000008280 R14: 00002000000020c0 R15: 00007ff1e5bab032
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:419 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:465 [inline]
RIP: 0010:do_unlinkat+0x29c/0x5a0 fs/namei.c:4534
Code: 00 00 20 00 89 de e8 13 6a 98 ff 45 31 f6 81 fb 00 00 20 00 41 0f 95 c6 41 83 c6 eb 31 db e9 f4 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 04 02 00 00 41 8b 1f be 00 00 70 00 21
RSP: 0018:ffffc9000126fde0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88812e4b9300 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000126fee0 R08: ffff8881f6e50c47 R09: 1ffff1103edca188
R10: dffffc0000000000 R11: ffffed103edca189 R12: ffff88811fc48000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000008
FS: 00007ff1e5afe6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1e5baac7c CR3: 00000001057b8000 CR4: 00000000003526b0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 20 00 and %al,(%rax)
4: 89 de mov %ebx,%esi
6: e8 13 6a 98 ff call 0xff986a1e
b: 45 31 f6 xor %r14d,%r14d
e: 81 fb 00 00 20 00 cmp $0x200000,%ebx
14: 41 0f 95 c6 setne %r14b
18: 41 83 c6 eb add $0xffffffeb,%r14d
1c: 31 db xor %ebx,%ebx
1e: e9 f4 00 00 00 jmp 0x117
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 04 02 00 00 jne 0x23b
37: 41 8b 1f mov (%r15),%ebx
3a: be 00 00 70 00 mov $0x700000,%esi
3f: 21 .byte 0x21
* Struck through repros no longer work on HEAD.