syzbot


BUG: MAX_LOCKDEP_KEYS too low!

Status: upstream: reported C repro on 2025/08/05 18:25
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+f38657e44df302e426f0@syzkaller.appspotmail.com
First crash: 16d, last: 1d05h
Bug presence (1)
Date Name Commit Repro Result
2025/08/10 upstream (ToT) 2b38afce25c4 C [report] BUG: MAX_LOCKDEP_KEYS too low!
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 BUG: MAX_LOCKDEP_KEYS too low! origin:lts-only -1 C error 11 3d21h 886d 0/3 upstream: reported C repro on 2023/03/20 08:38
upstream BUG: MAX_LOCKDEP_KEYS too low! net -1 C done error 3496 1882d 2126d 15/29 fixed on 2020/12/09 20:00
upstream BUG: MAX_LOCKDEP_KEYS too low! (2) no-reminders nfc -1 C unreliable 6066 1h47m 1555d 0/29 upstream: reported C repro on 2021/05/19 17:35
linux-6.1 BUG: MAX_LOCKDEP_KEYS too low! origin:upstream -1 C error 34 10d 866d 0/3 upstream: reported C repro on 2023/04/09 03:19

Sample crash report:
BUG: MAX_LOCKDEP_KEYS too low!
turning off the locking correctness validator.
CPU: 1 PID: 42 Comm: kworker/u4:2 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 register_lock_class+0x6c0/0x890 kernel/locking/lockdep.c:1321
 __lock_acquire+0x17a/0x7c80 kernel/locking/lockdep.c:5014
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 dev_reset_queue+0xfa/0x1a0 net/sched/sch_generic.c:1305
 netdev_for_each_tx_queue include/linux/netdevice.h:2520 [inline]
 dev_deactivate_many+0x6c5/0xcb0 net/sched/sch_generic.c:1373
 dev_deactivate+0x110/0x1a0 net/sched/sch_generic.c:1396
 linkwatch_do_dev+0x105/0x160 net/core/link_watch.c:189
 __linkwatch_run_queue+0x40f/0x660 net/core/link_watch.c:244
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:287
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/21 08:07 linux-6.6.y bb9c90ab9c5a 0b9605c8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: MAX_LOCKDEP_KEYS too low!
2025/08/06 18:29 linux-6.6.y 3a8ababb8b6a ffe1dd46 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: MAX_LOCKDEP_KEYS too low!
2025/08/05 18:24 linux-6.6.y 3a8ababb8b6a 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan BUG: MAX_LOCKDEP_KEYS too low!
* Struck through repros no longer work on HEAD.