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: syz.2.2796/18024 Modules linked in: CPU: 1 UID: 0 PID: 18024 Comm: syz.2.2796 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 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 12 da 0e 89 de <67> 48 0f b9 3a 5b 5d e9 c2 82 46 0a cc 48 c7 c7 c8 d5 5a 8e e8 05 RSP: 0018:ffffc9001b7ee4a8 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 9c733d5da57bd200 RDX: ffffc90004faa000 RSI: 00000000ffffffff RDI: ffffffff907da960 RBP: 0000000000000001 R08: ffffc9001b7ee227 R09: 1ffff920036fdc44 R10: dffffc0000000000 R11: fffff520036fdc45 R12: 0000000000000061 R13: ffffffff943f3680 R14: ffffffff9723dce8 R15: ffffffff9723e618 FS: 00007f87d39e76c0(0000) GS:ffff888124dc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c2bc14563 CR3: 0000000047c8e000 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 dc 43 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 62 67 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 e0 46 0a cc 48 8d 3d 87 6a da RSP: 0018:ffffc9001b7ee908 EFLAGS: 00000282 RAX: 9c733d5da57bd200 RBX: 0000000000000001 RCX: 8000000000000402 RDX: ffff88807bf2ab40 RSI: ffffffff8e69ef61 RDI: ffffffff8c6dac80 RBP: ffff88807bf29f40 R08: 0000000000000008 R09: ffffffff96c246b0 R10: 00000000068ed972 R11: 000000000e28502c R12: ffff888040d09170 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 __dev_close net/core/dev.c:1811 [inline] __dev_change_flags+0x3f5/0x820 net/core/dev.c:9821 netif_change_flags+0x7c/0x1b0 net/core/dev.c:9888 do_setlink+0xdd6/0x47a0 net/core/rtnetlink.c:3284 rtnl_group_changelink net/core/rtnetlink.c:3946 [inline] __rtnl_newlink net/core/rtnetlink.c:4112 [inline] rtnl_newlink+0x147c/0x1c30 net/core/rtnetlink.c:4242 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7159 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2712 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2766 __sys_sendmsg net/socket.c:2798 [inline] __do_sys_sendmsg net/socket.c:2803 [inline] __se_sys_sendmsg net/socket.c:2801 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2801 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f87d2b9e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f87d39e7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f87d2e25fa0 RCX: 00007f87d2b9e159 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000008 RBP: 00007f87d2c3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87d2e26038 R14: 00007f87d2e25fa0 R15: 00007ffe3c3a5228 ---------------- 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 12 da 0e lea 0xeda12d0(%rip),%rdi # 0xeda12f8 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 82 46 0a jmp 0xa4682f8 36: cc int3 37: 48 c7 c7 c8 d5 5a 8e mov $0xffffffff8e5ad5c8,%rdi 3e: e8 .byte 0xe8 3f: 05 .byte 0x5