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#1: kworker/u8:3/50 Modules linked in: CPU: 1 UID: 0 PID: 50 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 47 eb 37 03 89 c5 e8 c0 85 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d e0 fa d9 0e 89 de <67> 48 0f b9 3a 5b 5d e9 02 8c 45 0a cc 48 c7 c7 40 a0 5a 8e e8 45 RSP: 0018:ffffc90000bb7068 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 86688a8044ccdb00 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff907d8830 RBP: 0000000000000001 R08: ffffc90000bb6de7 R09: 1ffff92000176dbc R10: dffffc0000000000 R11: fffff52000176dbd R12: 000000000000005b R13: ffffffff9445fe28 R14: ffffffff973c9868 R15: ffffffff973c98d8 FS: 0000000000000000(0000) GS:ffff888124dcd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa82567820d 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 50 e5 42 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 a2 00 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 bf e9 45 0a cc 48 8d 3d 97 52 da RSP: 0018:ffffc90000bb74c8 EFLAGS: 00000282 RAX: 86688a8044ccdb00 RBX: 0000000000000001 RCX: 8000000000000402 RDX: ffff88801bbaea38 RSI: ffffffff8e69bb10 RDI: ffffffff8c6da080 RBP: ffff88801bbaddc0 R08: 0000000000000008 R09: ffffffff96ce8ca0 R10: 00000000500d8bc2 R11: 000000007bea95b3 R12: ffff88803b7a1170 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:1782 netif_close_many+0x249/0x660 net/core/dev.c:1824 unregister_netdevice_many_notify+0xb76/0x2140 net/core/dev.c:12487 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 47 eb 37 03 call 0x337eb58 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 e0 fa d9 0e lea 0xed9fae0(%rip),%rdi # 0xed9fb08 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 02 8c 45 0a jmp 0xa458c38 36: cc int3 37: 48 c7 c7 40 a0 5a 8e mov $0xffffffff8e5aa040,%rdi 3e: e8 .byte 0xe8 3f: 45 rex.RB