Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning: ------------[ cut here ]------------ lockdep bfs error:-1 WARNING: kernel/locking/lockdep.c:2103 at print_bfs_bug+0x20/0x40 kernel/locking/lockdep.c:2103, CPU#0: kworker/u8:85/23948 Modules linked in: CPU: 0 UID: 0 PID: 23948 Comm: kworker/u8:85 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: netns cleanup_net RIP: 0010:print_bfs_bug+0x22/0x40 kernel/locking/lockdep.c:2103 Code: 90 90 90 90 90 90 90 90 55 53 89 fb e8 c7 2d 38 03 89 c5 e8 c0 85 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d d0 07 da 0e 89 de <67> 48 0f b9 3a 5b 5d e9 c2 a2 46 0a cc 48 c7 c7 c1 d1 5a 8e e8 05 RSP: 0000:ffffc90004ef7068 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 185095e342413100 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff907d9e60 RBP: 0000000000000001 R08: ffffc90004ef6de7 R09: 1ffff920009dedbc R10: dffffc0000000000 R11: fffff520009dedbd R12: 0000000000000015 R13: ffffffff9442c9b8 R14: ffffffff972f7ad8 R15: ffffffff972f7b48 FS: 0000000000000000(0000) GS:ffff888124cc5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f626bc1e937 CR3: 000000000eb48000 CR4: 00000000003526f0 Call Trace: check_irq_usage kernel/locking/lockdep.c:-1 [inline] check_prev_add kernel/locking/lockdep.c:3213 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x25ed/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73 ktime_get+0x45/0x220 kernel/time/timekeeping.c:1002 clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363 hrtimer_rearm kernel/time/hrtimer.c:2176 [inline] __hrtimer_rearm_deferred+0x36c/0x4b0 kernel/time/hrtimer.c:2196 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:58 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:67 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline] irqentry_exit+0x8d3/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947 Code: ff ff ff e8 40 fc 43 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 62 77 f2 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 7f 00 47 0a cc 48 8d 3d 87 5f da RSP: 0000:ffffc90004ef74c8 EFLAGS: 00000282 RAX: 185095e342413100 RBX: 0000000000000001 RCX: 8000000000000402 RDX: ffff888066890c78 RSI: ffffffff8e69e7fa RDI: ffffffff8c6dac80 RBP: ffff888066890000 R08: 0000000000000008 R09: ffffffff96d15a88 R10: 00000000313bcd63 R11: 0000000061133b1a R12: ffff88808bbcc170 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:182 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:205 spin_lock_bh include/linux/spinlock.h:353 [inline] dev_reset_queue+0x138/0x1b0 include/net/sch_generic.h:754 netdev_for_each_tx_queue include/linux/netdevice.h:2747 [inline] dev_deactivate_many+0x778/0xda0 net/sched/sch_generic.c:1394 __dev_close_many+0x180/0x6e0 net/core/dev.c:1817 netif_close_many+0x249/0x660 net/core/dev.c:1859 unregister_netdevice_many_notify+0xb76/0x2140 net/core/dev.c:12535 ops_exit_rtnl_list net/core/net_namespace.c:188 [inline] ops_undo_list+0x391/0x8d0 net/core/net_namespace.c:249 cleanup_net+0x572/0x810 net/core/net_namespace.c:706 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 55 push %rbp 9: 53 push %rbx a: 89 fb mov %edi,%ebx c: e8 c7 2d 38 03 call 0x3382dd8 11: 89 c5 mov %eax,%ebp 13: e8 c0 85 ff ff call 0xffff85d8 18: 85 ed test %ebp,%ebp 1a: 74 13 je 0x2f 1c: 83 fb ff cmp $0xffffffff,%ebx 1f: 74 16 je 0x37 21: 48 8d 3d d0 07 da 0e lea 0xeda07d0(%rip),%rdi # 0xeda07f8 28: 89 de mov %ebx,%esi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 5b pop %rbx 30: 5d pop %rbp 31: e9 c2 a2 46 0a jmp 0xa46a2f8 36: cc int3 37: 48 c7 c7 c1 d1 5a 8e mov $0xffffffff8e5ad1c1,%rdi 3e: e8 .byte 0xe8 3f: 05 .byte 0x5