syzbot
general protection fault in detach_timer (2)
Status:
auto-obsoleted due to no activity on 2026/05/09 18:57
Subsystems:
kernel
[Documentation on labels]
Reported-by: syzbot+1a48e52497e1769b08de@syzkaller.appspotmail.com
First crash: 159d, last: 145d
Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000025: 0000 [#1] SMP KASAN PTI
KASAN: maybe wild-memory-access in range [0xdead000000000128-0xdead00000000012f]
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__hlist_del include/linux/list.h:994 [inline]
RIP: 0010:detach_timer+0x120/0x300 kernel/time/timer.c:891
Code: c1 e8 03 80 3c 28 00 74 08 4c 89 e7 e8 39 bd 79 00 4d 89 3c 24 4d 85 ff 74 46 e8 fb b2 13 00 49 83 c7 08 4c 89 f8 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 ff e8 12 bd 79 00 4d 89 27 80 7c 24 04 00
RSP: 0018:ffffc90000a3faf8 EFLAGS: 00010802
RAX: 1bd5a00000000025 RBX: 1ffff11009b8052d RCX: ffff88801d2bbc80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1ed45b7 R12: ffffc90000a3fc00
R13: ffff88804dc02970 R14: 1ffff11009b8052e R15: dead00000000012a
FS: 0000000000000000(0000) GS:ffff888126442000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa992574ff8 CR3: 0000000033028000 CR4: 00000000003526f0
Call Trace:
<TASK>
expire_timers kernel/time/timer.c:1782 [inline]
__run_timers kernel/time/timer.c:2373 [inline]
__run_timer_base+0x624/0x9f0 kernel/time/timer.c:2385
run_timer_base kernel/time/timer.c:2394 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1138
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__hlist_del include/linux/list.h:994 [inline]
RIP: 0010:detach_timer+0x120/0x300 kernel/time/timer.c:891
Code: c1 e8 03 80 3c 28 00 74 08 4c 89 e7 e8 39 bd 79 00 4d 89 3c 24 4d 85 ff 74 46 e8 fb b2 13 00 49 83 c7 08 4c 89 f8 48 c1 e8 03 <80> 3c 28 00 74 08 4c 89 ff e8 12 bd 79 00 4d 89 27 80 7c 24 04 00
RSP: 0018:ffffc90000a3faf8 EFLAGS: 00010802
RAX: 1bd5a00000000025 RBX: 1ffff11009b8052d RCX: ffff88801d2bbc80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1ed45b7 R12: ffffc90000a3fc00
R13: ffff88804dc02970 R14: 1ffff11009b8052e R15: dead00000000012a
FS: 0000000000000000(0000) GS:ffff888126442000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa992574ff8 CR3: 0000000033028000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: c1 e8 03 shr $0x3,%eax
3: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1)
7: 74 08 je 0x11
9: 4c 89 e7 mov %r12,%rdi
c: e8 39 bd 79 00 call 0x79bd4a
11: 4d 89 3c 24 mov %r15,(%r12)
15: 4d 85 ff test %r15,%r15
18: 74 46 je 0x60
1a: e8 fb b2 13 00 call 0x13b31a
1f: 49 83 c7 08 add $0x8,%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ff mov %r15,%rdi
33: e8 12 bd 79 00 call 0x79bd4a
38: 4d 89 27 mov %r12,(%r15)
3b: 80 7c 24 04 00 cmpb $0x0,0x4(%rsp)
* Struck through repros no longer work on HEAD.