Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning: ------------[ cut here ]------------ lockdep bfs error:-1 WARNING: kernel/locking/lockdep.c:2059 at print_bfs_bug+0x20/0x40 kernel/locking/lockdep.c:2059, CPU#1: syz.4.2217/14983 Modules linked in: CPU: 1 UID: 0 PID: 14983 Comm: syz.4.2217 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:print_bfs_bug+0x22/0x40 kernel/locking/lockdep.c:2059 Code: 90 90 90 90 90 90 90 90 55 53 89 fb e8 77 a8 2c 03 89 c5 e8 90 89 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d 40 22 b8 0e 89 de <67> 48 0f b9 3a 5b 5d e9 92 a6 2e 0a cc 48 c7 c7 e3 dc 3b 8e e8 95 RSP: 0018:ffffc9000395e530 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 3a55508951adf100 RDX: ffffc900111cf000 RSI: 00000000ffffffff RDI: ffffffff905aa1c0 RBP: 0000000000000001 R08: ffffc9000395e2a7 R09: 1ffff9200072bc54 R10: dffffc0000000000 R11: fffff5200072bc55 R12: 0000000000000052 R13: ffffffff941e2478 R14: ffff888055e8be00 R15: ffffffff97139618 FS: 00007fcfd7ba86c0(0000) GS:ffff888125060000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f70b5f4b162 CR3: 000000002ab1a000 CR4: 00000000003526f0 Call Trace: check_irq_usage kernel/locking/lockdep.c:-1 [inline] check_prev_add kernel/locking/lockdep.c:3169 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x24f0/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73 ktime_expiry_to_cycles+0x4e/0x1e0 kernel/time/timekeeping.c:910 clockevent_set_next_coupled kernel/time/clockevents.c:314 [inline] clockevents_program_event+0x199/0x630 kernel/time/clockevents.c:360 hrtimer_rearm kernel/time/hrtimer.c:2141 [inline] __hrtimer_rearm_deferred+0x26c/0x420 kernel/time/hrtimer.c:2161 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [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+0x8b7/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 41 00 2c 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 2b db c9 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 10 01 2f 0a cc 48 8d 3d b8 76 b8 RSP: 0018:ffffc9000395e9b0 EFLAGS: 00000282 RAX: 3a55508951adf100 RBX: 0000000000000000 RCX: 0000000080000201 RDX: ffffffff942782e8 RSI: ffffffff8e4ae976 RDI: ffffffff8c4bd280 RBP: ffffffff89c4338e R08: 0000000000000008 R09: ffffffff969aaf78 R10: 00000000e05e2c3b R11: 00000000e928e660 R12: 0000000000000000 R13: ffff888080b18170 R14: 0000000000000001 R15: 0000000000000246 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:182 spin_lock_bh include/linux/spinlock.h:348 [inline] some_qdisc_is_busy net/sched/sch_generic.c:1352 [inline] dev_deactivate_many+0xade/0xda0 net/sched/sch_generic.c:1404 dev_deactivate net/sched/sch_generic.c:1419 [inline] dev_qdisc_change_tx_queue_len+0x185/0x530 net/sched/sch_generic.c:1475 netif_change_tx_queue_len+0x184/0x290 net/core/dev.c:9934 do_setlink+0xf9c/0x4670 net/core/rtnetlink.c:3238 rtnl_group_changelink net/core/rtnetlink.c:3863 [inline] __rtnl_newlink net/core/rtnetlink.c:4031 [inline] rtnl_newlink+0x148e/0x1bd0 net/core/rtnetlink.c:4159 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcfd6d9de59 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:00007fcfd7ba8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fcfd7026090 RCX: 00007fcfd6d9de59 RDX: 0000000004000c00 RSI: 0000200000000180 RDI: 0000000000000004 RBP: 00007fcfd6e33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcfd7026128 R14: 00007fcfd7026090 R15: 00007ffe2e0f9068 ---------------- 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 77 a8 2c 03 call 0x32ca888 11: 89 c5 mov %eax,%ebp 13: e8 90 89 ff ff call 0xffff89a8 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 40 22 b8 0e lea 0xeb82240(%rip),%rdi # 0xeb82268 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 92 a6 2e 0a jmp 0xa2ea6c8 36: cc int3 37: 48 c7 c7 e3 dc 3b 8e mov $0xffffffff8e3bdce3,%rdi 3e: e8 .byte 0xe8 3f: 95 xchg %eax,%ebp