syzbot

watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [syz.1.1034:8015]
Modules linked in:
irq event stamp: 1149215
hardirqs last  enabled at (1149214): [<ffff8000083b9458>] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
hardirqs last  enabled at (1149214): [<ffff8000083b9458>] timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
hardirqs last  enabled at (1149214): [<ffff8000083b9458>] timekeeping_get_ns+0x124/0x3b8 kernel/time/timekeeping.c:388
hardirqs last disabled at (1149215): [<ffff800011956d60>] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline]
hardirqs last disabled at (1149215): [<ffff800011956d60>] el1_interrupt+0x24/0x54 arch/arm64/kernel/entry-common.c:486
softirqs last  enabled at (9574): [<ffff80000803092c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (9579): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:630
CPU: 1 PID: 8015 Comm: syz.1.1034 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400005 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __sanitizer_cov_trace_pc+0x24/0x94 kernel/kcov.c:212
lr : cake_heapify+0x30/0x530 net/sched/sch_cake.c:1476
sp : ffff800008017180
x29: ffff8000080171a0 x28: dfff800000000000 x27: 0000002e977bb6bd
x26: 000000000003e8f8 x25: ffff000103f942d8 x24: 0000000000000000
x23: ffff000103f902d0 x22: ffff000103f902c0 x21: ffff000103f902c0
x20: 0000000000000500 x19: 0000000000000903 x18: ffff800011abbcc0
x17: ffff8000181f9000 x16: ffff8000082d22d4 x15: ffff800017cd9fc0
x14: ffff0000d34da658 x13: 1ffff00002a180b1 x12: 0000000000ff0100
x11: ff0080000ffc8fbc x10: 0000000000000302 x9 : ffff80000ffc8fbc
x8 : ffff0000d34d9bc0 x7 : ffff8000083b9864 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000002 x1 : 0000000000000903 x0 : ffff000103f902c0
Call trace:
 __sanitizer_cov_trace_pc+0x24/0x94 kernel/kcov.c:212
 cake_drop net/sched/sch_cake.c:1575 [inline]
 cake_enqueue+0x32dc/0x6670 net/sched/sch_cake.c:1948
 qdisc_enqueue include/net/sch_generic.h:816 [inline]
 tbf_enqueue+0x2dc/0x610 net/sched/sch_tbf.c:257
 dev_qdisc_enqueue+0x5c/0x38c net/core/dev.c:3875
 __dev_xmit_skb net/core/dev.c:3964 [inline]
 __dev_queue_xmit+0xad0/0x309c net/core/dev.c:4312
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 tipc_l2_send_msg+0x29c/0x35c net/tipc/bearer.c:518
 tipc_bearer_xmit_skb+0x244/0x384 net/tipc/bearer.c:577
 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338
 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x460/0x6bc kernel/time/timer.c:1820
 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833
 handle_softirqs+0x318/0xc6c kernel/softirq.c:596
 __do_softirq+0x14/0x20 kernel/softirq.c:630
 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:897
 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85
 invoke_softirq kernel/softirq.c:477 [inline]
 __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679
 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691
 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
 el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581
 arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline]
 raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline]
 finish_lock_switch+0xb8/0x1c4 kernel/sched/core.c:5003
 finish_task_switch+0x120/0x620 kernel/sched/core.c:5121
 context_switch kernel/sched/core.c:5247 [inline]
 __schedule+0xde0/0x1b18 kernel/sched/core.c:6561
 preempt_schedule_common+0xec/0x1a0 kernel/sched/core.c:6730
 preempt_schedule+0x64/0x84 kernel/sched/core.c:6754
 __local_bh_enable_ip+0x21c/0x380 kernel/softirq.c:428
 local_bh_enable+0x28/0x34 include/linux/bottom_half.h:33
 put_cpu_fpsimd_context arch/arm64/kernel/fpsimd.c:276 [inline]
 fpsimd_restore_current_state+0xe8/0x20c arch/arm64/kernel/fpsimd.c:1768
 do_notify_resume+0x1784/0x2b0c arch/arm64/kernel/signal.c:1140
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585