syzbot


WARNING in stub_timer

Status: upstream: reported on 2026/01/08 22:43
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+19e796f043fe3be7b76a@syzkaller.appspotmail.com
First crash: 56d, last: 8h40m
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [wireguard?] WARNING in stub_timer 0 (1) 2026/01/08 22:43

Sample crash report:
------------[ cut here ]------------
1
WARNING: kernel/time/timer.c:716 at stub_timer+0xa/0x20 kernel/time/timer.c:716, CPU#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:stub_timer+0xa/0x20 kernel/time/timer.c:716
Code: 0f 94 c0 5b 41 5e e9 05 2d 75 09 cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 f7 bc 13 00 90 <0f> 0b 90 c3 cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000157a38 EFLAGS: 00010246
RAX: ffffffff81b09639 RBX: 0000000080000000 RCX: ffff88801caa8000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: ffffc90000157b30 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: ffffffff81b09630 R12: 0000000000000000
R13: 0000000100001040 R14: 1ffff9200002af4c R15: ffff888064321f38
FS:  0000000000000000(0000) GS:ffff888126340000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6720045900 CR3: 0000000020776000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x6a3/0x9f0 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>

Crashes (209):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/02 09:24 upstream 39c633261414 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/03/01 22:09 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 18:54 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 17:22 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 16:35 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 14:06 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 09:25 upstream 42eb01783091 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 08:09 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/03/01 06:06 upstream 42eb01783091 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 04:55 upstream 42eb01783091 43249bac .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/03/01 00:00 upstream 42eb01783091 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/28 23:00 upstream 42eb01783091 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/28 21:26 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/28 19:09 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/28 17:48 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/28 14:18 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/28 10:22 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/28 09:14 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/28 03:33 upstream aed968f8a6cd 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/28 01:04 upstream aed968f8a6cd 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 21:39 upstream a75cb869a8cc 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 20:30 upstream a75cb869a8cc 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 16:45 upstream a75cb869a8cc 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 09:16 upstream a75cb869a8cc a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 06:44 upstream a75cb869a8cc a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 06:35 upstream a75cb869a8cc a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/27 03:32 upstream 3f4a08e64442 a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/26 21:17 upstream f4d0ec0aa20d ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/26 19:58 upstream f4d0ec0aa20d ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/26 18:21 upstream f4d0ec0aa20d ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/26 13:39 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/26 11:37 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/26 09:55 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/26 05:10 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/25 23:52 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/25 20:04 upstream d9d32e5bd5a4 94a9671e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/25 17:15 upstream 7dff99b35460 df2e85d4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/25 07:49 upstream 7dff99b35460 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/25 03:15 upstream 7dff99b35460 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/25 01:43 upstream 7dff99b35460 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/24 23:13 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/24 21:45 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/24 19:58 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/24 17:49 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in stub_timer
2026/02/24 15:37 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/24 12:43 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in stub_timer
2026/02/05 14:35 upstream f14faaf3a1fb 4936e85c .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in stub_timer
2026/01/04 22:26 upstream 54e82e93ca93 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in stub_timer
* Struck through repros no longer work on HEAD.