watchdog: BUG: soft lockup - CPU#0 stuck for 116s! [syz.5.5243:1330] Modules linked in: irq event stamp: 19390993 hardirqs last enabled at (19390992): [] irqentry_exit+0x59c/0x620 kernel/entry/common.c:219 hardirqs last disabled at (19390993): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (19269738): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (19269738): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (19269738): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 softirqs last disabled at (19269743): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (19269743): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (19269743): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 CPU: 0 UID: 0 PID: 1330 Comm: syz.5.5243 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:strlen+0x32/0x70 lib/string.c:420 Code: 41 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 11 <48> ff c3 49 8d 47 01 42 80 7c 3f 01 00 75 de eb 19 89 d9 80 e1 07 RSP: 0018:ffffc900000060f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8badfbac RCX: ffff88802f673d00 RDX: ffffffff851b8b4d RSI: ffffffff8e55a420 RDI: ffffffff8badfba0 RBP: ffffc90000006208 R08: ffffffff851b8b4d R09: ffffffff8e55a420 R10: ffffc90000005ec8 R11: fffff52000000bdb R12: dffffc0000000000 R13: ffffffff851b8b4d R14: dffffc0000000000 R15: 000000000000000b FS: 00007f75ffc276c0(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcf5279630 CR3: 000000007b9fa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __fortify_strlen include/linux/fortify-string.h:268 [inline] trace_event_get_offsets_lock include/trace/events/lock.h:50 [inline] do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0xce/0x3f0 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x379/0x3a0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:979 [inline] pfn_valid include/linux/mmzone.h:2194 [inline] sg_phys+0x4ab/0x580 include/linux/scatterlist.h:412 vring_map_one_sg+0x288/0x580 drivers/virtio/virtio_ring.c:402 virtqueue_add_split drivers/virtio/virtio_ring.c:608 [inline] virtqueue_add+0x570/0x42a0 drivers/virtio/virtio_ring.c:2281 virtqueue_add_outbuf+0xa3/0xf0 drivers/virtio/virtio_ring.c:2342 virtnet_add_outbuf drivers/net/virtio_net.c:571 [inline] xmit_skb drivers/net/virtio_net.c:3313 [inline] start_xmit+0x12c6/0x2c90 drivers/net/virtio_net.c:3337 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3866 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4182 [inline] __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4798 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0xbb6/0xff0 net/ipv4/ip_output.c:237 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:438 ip_local_out net/ipv4/ip_output.c:131 [inline] __ip_queue_xmit+0x1198/0x1be0 net/ipv4/ip_output.c:534 __tcp_transmit_skb+0x253b/0x3ad0 net/ipv4/tcp_output.c:1631 tcp_rcv_established+0x18de/0x25b0 net/ipv4/tcp_input.c:6435 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1881 tcp_v4_rcv+0x2d27/0x3780 net/ipv4/tcp_ipv4.c:2324 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 dst_input include/net/dst.h:474 [inline] ip_sublist_rcv_finish+0x221/0x2a0 net/ipv4/ip_input.c:584 ip_list_rcv_finish net/ipv4/ip_input.c:636 [inline] ip_sublist_rcv+0x761/0xa70 net/ipv4/ip_input.c:644 ip_list_rcv+0x3f1/0x450 net/ipv4/ip_input.c:678 __netif_receive_skb_list_ptype net/core/dev.c:6195 [inline] __netif_receive_skb_list_core+0x57c/0x810 net/core/dev.c:6232 __netif_receive_skb_list net/core/dev.c:6294 [inline] netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6385 gro_normal_list include/net/gro.h:524 [inline] gro_flush_normal include/net/gro.h:532 [inline] napi_complete_done+0x299/0x730 net/core/dev.c:6754 virtqueue_napi_complete drivers/net/virtio_net.c:749 [inline] virtnet_poll+0x259e/0x2fe0 drivers/net/virtio_net.c:3091 __napi_poll+0xae/0x340 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7896 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_unlock_special+0x1d/0x420 kernel/rcu/tree_plugin.h:770 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 8b 2d 7b 50 48 11 f7 c5 00 00 f0 00 74 14 <48> 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d e9 90 73 ef 09 cc 49 89 RSP: 0018:ffffc90003357600 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000246 RCX: 0000000000000001 RDX: 0000000000000006 RSI: ffffffff8dcc9112 RDI: ffffffff8c073980 RBP: ffff8881256f5000 R08: ffffffff8fef1a77 R09: 1ffffffff1fde34e R10: dffffc0000000000 R11: fffffbfff1fde34f R12: ffffffff8e560578 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b863b8e8 __rcu_read_unlock+0x83/0xe0 kernel/rcu/tree_plugin.h:438 rcu_read_unlock include/linux/rcupdate.h:899 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x1aaf/0x23c0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3239 __dentry_kill+0x469/0x5e0 fs/dcache.c:689 shrink_kill+0xa9/0x2c0 fs/dcache.c:1137 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1164 shrink_dcache_sb+0x23f/0x3c0 fs/dcache.c:1285 reconfigure_super+0x4fb/0x8a0 fs/super.c:1055 do_remount fs/namespace.c:3264 [inline] path_mount+0xdc5/0x10e0 fs/namespace.c:4014 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f75fed9aeb9 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:00007f75ffc27028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f75ff015fa0 RCX: 00007f75fed9aeb9 RDX: 0000000000000000 RSI: 0000200000000440 RDI: 0000000000000000 RBP: 00007f75fee08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000200020 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f75ff016038 R14: 00007f75ff015fa0 R15: 00007ffcb7ebfbf8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11899 Comm: kworker/u8:43 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:235 Code: 48 16 00 00 83 fa 02 75 21 48 8b 91 50 16 00 00 48 8b 32 48 8d 7e 01 8b 89 4c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 cc cc cc cc cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 RSP: 0018:ffffc9000bd87698 EFLAGS: 00000293 RAX: ffffffff81b89ffd RBX: 1ffff110170c856d RCX: ffff88807a8e9e80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000bd877e0 R08: ffffffff8fef1a77 R09: 1ffffffff1fde34e R10: dffffc0000000000 R11: fffffbfff1fde34f R12: ffff8880b8642b68 R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881257f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fac6b35d000 CR3: 000000000e346000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xcfd/0x1270 kernel/smp.c:877 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2921 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:879 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246