watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz.3.348:5718] Modules linked in: irq event stamp: 1290327 hardirqs last enabled at (1290326): [] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] hardirqs last enabled at (1290326): [] timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] hardirqs last enabled at (1290326): [] timekeeping_get_ns+0x120/0x3b8 kernel/time/timekeeping.c:388 hardirqs last disabled at (1290327): [] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline] hardirqs last disabled at (1290327): [] el1_interrupt+0x24/0x54 arch/arm64/kernel/entry-common.c:486 softirqs last enabled at (31558): [] softirq_handle_end kernel/softirq.c:439 [inline] softirqs last enabled at (31558): [] handle_softirqs+0xb1c/0xc90 kernel/softirq.c:624 softirqs last disabled at (46351): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 CPU: 0 PID: 5718 Comm: syz.3.348 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026 pstate: 02400005 (nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : check_kcov_mode kernel/kcov.c:178 [inline] pc : write_comp_data kernel/kcov.c:241 [inline] pc : __sanitizer_cov_trace_const_cmp2+0x28/0xac kernel/kcov.c:302 lr : cake_heap_get_backlog net/sched/sch_cake.c:1466 [inline] lr : cake_heapify+0x44/0x464 net/sched/sch_cake.c:1474 sp : ffff800008007100 x29: ffff800008007120 x28: 0000000000000000 x27: ffff0000ea300000 x26: 0000000000000000 x25: dfff800000000000 x24: 1fffe0001d46085b x23: ffff0000ea3042d8 x22: ffff0000ea3002c0 x21: 0000000000000f8a x20: 0000000000000f8a x19: 0000000000000f8a x18: 0000000000000000 x17: 0000000000000000 x16: ffff8000082dd25c x15: ffff8000184dd000 x14: 0000000000000001 x13: 1ffff00002a72071 x12: 00000000540d193d x11: ff008000101a37d4 x10: 0000000000000300 x9 : ffff0000d1c95400 x8 : ffff8000101a37d4 x7 : ffff8000083c7930 x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000002 x1 : 0000000000000f8a x0 : 0000000000002001 Call trace: __sanitizer_cov_trace_const_cmp2+0x28/0xac kernel/kcov.c:303 cake_drop net/sched/sch_cake.c:1571 [inline] cake_enqueue+0x36c0/0x6a18 net/sched/sch_cake.c:1945 qdisc_enqueue include/net/sch_generic.h:855 [inline] netem_dequeue+0xa00/0x1018 net/sched/sch_netem.c:736 dequeue_skb net/sched/sch_generic.c:295 [inline] qdisc_restart net/sched/sch_generic.c:400 [inline] __qdisc_run+0x1b4/0x1300 net/sched/sch_generic.c:418 __dev_xmit_skb net/core/dev.c:3995 [inline] __dev_queue_xmit+0xc38/0x3154 net/core/dev.c:4337 dev_queue_xmit include/linux/netdevice.h:3053 [inline] tipc_l2_send_msg+0x2a0/0x364 net/tipc/bearer.c:519 tipc_bearer_xmit_skb+0x240/0x380 net/tipc/bearer.c:578 tipc_disc_timeout+0x4e8/0x630 net/tipc/discover.c:340 call_timer_fn+0x1b8/0x96c kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x478/0x6d8 kernel/time/timer.c:2023 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:2036 handle_softirqs+0x318/0xc90 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/0x430 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_restore arch/arm64/include/asm/irqflags.h:122 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x120/0x184 kernel/sched/wait.c:208 __unix_dgram_recvmsg+0x38c/0xb24 net/unix/af_unix.c:2480 unix_dgram_recvmsg+0xd0/0xe8 net/unix/af_unix.c:2550 ____sys_recvmsg+0x270/0x754 net/socket.c:-1 ___sys_recvmsg net/socket.c:2780 [inline] do_recvmmsg+0x36c/0x9d8 net/socket.c:2874 __sys_recvmmsg net/socket.c:2953 [inline] __do_sys_recvmmsg net/socket.c:2976 [inline] __se_sys_recvmmsg net/socket.c:2969 [inline] __arm64_sys_recvmmsg+0x184/0x244 net/socket.c:2969 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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