Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning: ------------[ cut here ]------------ lockdep bfs error:-1 WARNING: kernel/locking/lockdep.c:2075 at print_bfs_bug+0x20/0x40 kernel/locking/lockdep.c:2075, CPU#1: syz.4.1525/12361 Modules linked in: CPU: 1 UID: 0 PID: 12361 Comm: syz.4.1525 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:print_bfs_bug+0x22/0x40 kernel/locking/lockdep.c:2075 Code: 90 90 90 90 90 90 90 90 55 53 89 fb e8 d7 4a 36 03 89 c5 e8 c0 85 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d e0 ca d9 0e 89 de <67> 48 0f b9 3a 5b 5d e9 02 81 42 0a cc 48 c7 c7 32 7e 60 8e e8 65 RSP: 0018:ffffc9000398e548 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 09523d7e6c42ef00 RDX: ffffc9000f84c000 RSI: 00000000ffffffff RDI: ffffffff907d41b0 RBP: 0000000000000001 R08: ffffc9000398e2c7 R09: 1ffff92000731c58 R10: dffffc0000000000 R11: fffff52000731c59 R12: 0000000000000061 R13: ffffffff943d6d18 R14: ffff88802b1769e8 R15: ffffffff9721add8 FS: 00007ff7209e86c0(0000) GS:ffff888124de0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd68c8aba2e CR3: 000000007a3ba000 CR4: 00000000003526f0 Call Trace: check_irq_usage kernel/locking/lockdep.c:-1 [inline] check_prev_add kernel/locking/lockdep.c:3185 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x262d/0x2e50 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 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:2169 [inline] __hrtimer_rearm_deferred+0x36c/0x4b0 kernel/time/hrtimer.c:2189 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:5913 Code: ff ff ff e8 40 dc 3f 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 92 e7 f0 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 07 23 da RSP: 0018:ffffc9000398e9b0 EFLAGS: 00000292 RAX: 09523d7e6c42ef00 RBX: 0000000000000001 RCX: 8000000000000201 RDX: ffffffff944de648 RSI: ffffffff8e6fac39 RDI: ffffffff8c6d8b80 RBP: ffff88802b175dc0 R08: 0000000000000008 R09: ffffffff96c20298 R10: 00000000308f3d35 R11: 00000000e59c5a4a R12: ffff888036b78170 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] 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:9994 do_setlink+0xf9c/0x4670 net/core/rtnetlink.c:3289 rtnl_group_changelink net/core/rtnetlink.c:3919 [inline] __rtnl_newlink net/core/rtnetlink.c:4085 [inline] rtnl_newlink+0x146f/0x1c30 net/core/rtnetlink.c:4215 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bd/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:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2713 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767 __sys_sendmsg net/socket.c:2799 [inline] __do_sys_sendmsg net/socket.c:2804 [inline] __se_sys_sendmsg net/socket.c:2802 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802 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: 0033:0x7ff71fb9e159 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:00007ff7209e8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff71fe25fa0 RCX: 00007ff71fb9e159 RDX: 0000000004000c00 RSI: 0000200000000180 RDI: 000000000000000f RBP: 00007ff71fc35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff71fe26038 R14: 00007ff71fe25fa0 R15: 00007fffcddbf3d8 ---------------- 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 d7 4a 36 03 call 0x3364ae8 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 ca d9 0e lea 0xed9cae0(%rip),%rdi # 0xed9cb08 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 81 42 0a jmp 0xa428138 36: cc int3 37: 48 c7 c7 32 7e 60 8e mov $0xffffffff8e607e32,%rdi 3e: e8 .byte 0xe8 3f: 65 gs