watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz.1.234:5222] Modules linked in: irq event stamp: 1098623 hardirqs last enabled at (1098622): [] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] hardirqs last enabled at (1098622): [] timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] hardirqs last enabled at (1098622): [] timekeeping_get_ns+0x124/0x3b4 kernel/time/timekeeping.c:388 hardirqs last disabled at (1098623): [] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline] hardirqs last disabled at (1098623): [] el1_interrupt+0x24/0x54 arch/arm64/kernel/entry-common.c:486 softirqs last enabled at (428): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (429): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 CPU: 0 PID: 5222 Comm: syz.1.234 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : __sanitizer_cov_trace_const_cmp4+0x0/0xb0 kernel/kcov.c:312 lr : cake_heapify+0x1b0/0x530 net/sched/sch_cake.c:1494 sp : ffff800008007190 x29: ffff8000080071a0 x28: 0000000000000000 x27: 00000000000198d0 x26: 00000000000013e2 x25: 0000000000000000 x24: 00000000000009f1 x23: dfff800000000000 x22: 00000000000009f1 x21: 0000000000000000 x20: ffff000103d682d0 x19: 00000000000009f1 x18: 00000000c52f2e35 x17: ffff80001835b000 x16: ffff8000082d93d8 x15: ffff800017e3c000 x14: 0000000000000001 x13: 1ffff00002a44071 x12: 0000000000ff0100 x11: ff00800010066d20 x10: 0000000000000000 x9 : ffff0000da435340 x8 : ffff800010066d20 x7 : ffff8000083c1cf0 x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000002 x1 : 00000000000009f1 x0 : 0000000000000fff Call trace: __sanitizer_cov_trace_const_cmp4+0x0/0xb0 kernel/kcov.c:308 cake_drop net/sched/sch_cake.c:1575 [inline] cake_enqueue+0x3464/0x680c net/sched/sch_cake.c:1949 cbs_child_enqueue net/sched/sch_cbs.c:95 [inline] cbs_enqueue_soft+0x14c/0x230 net/sched/sch_cbs.c:128 cbs_enqueue+0x54/0x68 net/sched/sch_cbs.c:136 dev_qdisc_enqueue+0x5c/0x388 net/core/dev.c:3900 __dev_xmit_skb net/core/dev.c:3989 [inline] __dev_queue_xmit+0xaf8/0x3118 net/core/dev.c:4337 dev_queue_xmit include/linux/netdevice.h:3051 [inline] tipc_l2_send_msg+0x29c/0x35c net/tipc/bearer.c:518 tipc_bearer_xmit_skb+0x240/0x380 net/tipc/bearer.c:577 tipc_disc_timeout+0x4d8/0x628 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x95c kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x478/0x6f0 kernel/time/timer.c:2023 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:2036 handle_softirqs+0x318/0xc60 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 do_softirq+0xf8/0x1a8 kernel/softirq.c:497 __local_bh_enable_ip+0x250/0x37c kernel/softirq.c:421 local_bh_enable+0x28/0x34 include/linux/bottom_half.h:33 rcu_read_unlock_bh include/linux/rcupdate.h:861 [inline] __dev_queue_xmit+0x1720/0x3118 net/core/dev.c:4411 dev_queue_xmit include/linux/netdevice.h:3051 [inline] neigh_hh_output include/net/neighbour.h:529 [inline] neigh_output include/net/neighbour.h:543 [inline] ip6_finish_output2+0xd28/0x1840 net/ipv6/ip6_output.c:138 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline] ip6_finish_output+0x594/0x92c net/ipv6/ip6_output.c:216 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x274/0x500 net/ipv6/ip6_output.c:237 dst_output include/net/dst.h:453 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0x119c/0x1b08 net/ipv6/ip6_output.c:360 sctp_v6_xmit+0x818/0xf20 net/sctp/ipv6.c:250 sctp_packet_transmit+0x1dec/0x22d4 net/sctp/output.c:653 sctp_packet_singleton+0x1dc/0x2d0 net/sctp/outqueue.c:783 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline] sctp_outq_flush+0x410/0x27d0 net/sctp/outqueue.c:1212 sctp_outq_uncork+0x84/0xc0 net/sctp/outqueue.c:764 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x41dc/0x481c net/sctp/sm_sideeffect.c:1170 sctp_primitive_ASSOCIATE+0x98/0xc8 net/sctp/primitive.c:73 sctp_sendmsg_to_asoc+0xce0/0x1354 net/sctp/socket.c:1838 sctp_sendmsg+0x13a8/0x20b4 net/sctp/socket.c:2028 inet_sendmsg+0x154/0x284 net/ipv4/af_inet.c:841 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5c8/0x938 net/socket.c:2518 ___sys_sendmsg net/socket.c:2572 [inline] __sys_sendmsg+0x288/0x374 net/socket.c:2601 __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg net/socket.c:2608 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2608 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585