watchdog: BUG: soft lockup - CPU#0 stuck for 225s! [syz.3.264:1460]
Modules linked in:
CPU: 0 PID: 1460 Comm: syz.3.264 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x56/0x80 kernel/locking/spinlock.c:194
Code: 46 6d 86 e8 8c a6 f4 fc 4c 89 f7 48 83 3d a9 af b8 01 00 74 31 e8 fe 5f 9b fc 66 90 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> f5 2d 93 fc 65 8b 05 56 d6 4d 7b 85 c0 74 05 5b 41 5e 5d c3 e8
RSP: 0018:ffffc90000007800 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000286 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: 0000000000000286 RDI: 0000000000000001
RBP: ffffc90000007810 R08: ffffffff870c5008 R09: ffffffff870c5018
R10: ffffffff870c5003 R11: 1ffffffff0e18a00 R12: ffff8881081abb00
R13: 0000000000000286 R14: ffffea0008ffd028 R15: 1ffff92000000f10
FS:  00007f20791896c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000011e44c000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 kfence_guarded_alloc+0x8bf/0xbc0 mm/kfence/core.c:419
 __kfence_alloc+0x30e/0x340 mm/kfence/core.c:969
 kfence_alloc include/linux/kfence.h:126 [inline]
 slab_alloc_node mm/slub.c:3163 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc+0x1b9/0x260 mm/slub.c:3260
 kmem_cache_alloc_node include/linux/slab.h:492 [inline]
 __alloc_skb+0xe4/0x730 net/core/skbuff.c:416
 alloc_skb include/linux/skbuff.h:1183 [inline]
 wg_packet_send_keepalive+0x62/0x1c0 drivers/net/wireguard/send.c:226
 wg_expired_send_keepalive+0x2e/0x1b0 drivers/net/wireguard/timers.c:83
 call_timer_fn+0x38/0x290 kernel/time/timer.c:1459
 expire_timers kernel/time/timer.c:1504 [inline]
 __run_timers+0x637/0x9a0 kernel/time/timer.c:1775
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1788
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 __do_softirq kernel/softirq.c:621 [inline]
 invoke_softirq kernel/softirq.c:443 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline]
RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline]
RIP: 0010:__mutex_owner kernel/locking/mutex.c:82 [inline]
RIP: 0010:mutex_spin_on_owner+0x2dd/0x460 kernel/locking/mutex.c:363
Code: ef be 08 00 00 00 e8 f2 8f 59 00 43 80 3c 34 00 74 08 4c 89 ef e8 03 8e 59 00 49 f7 45 00 01 00 00 00 0f 85 30 01 00 00 f3 90 <4c> 89 ef be 08 00 00 00 e8 c6 8f 59 00 43 80 3c 34 00 0f 84 63 fe
RSP: 0018:ffffc90000ba7460 EFLAGS: 00000246
RAX: ffff8881f7100000 RBX: ffff888119c83b40 RCX: ffffffff814fae71
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
RBP: ffffc90000ba7570 R08: ffff888119fb13c7 R09: 1ffff110233f6278
R10: dffffc0000000000 R11: ffffed10233f6279 R12: 1ffffffff0da31d4
R13: ffffffff86d18ea0 R14: dffffc0000000000 R15: 1ffff92000174e9c
 mutex_optimistic_spin kernel/locking/mutex.c:486 [inline]
 __mutex_lock_common kernel/locking/mutex.c:704 [inline]
 __mutex_lock+0x9a8/0x12d0 kernel/locking/mutex.c:756
 __mutex_lock_killable_slowpath+0xe/0x10 kernel/locking/mutex.c:1013
 mutex_lock_killable+0x114/0x1c0 kernel/locking/mutex.c:980
 rtnl_lock_killable+0x15/0x20 net/core/rtnetlink.c:78
 register_netdev+0x14/0x50 net/core/dev.c:10553
 vti6_init_net+0x300/0x3c0 net/ipv6/ip6_vti.c:1179
 ops_init+0x2c0/0x470 net/core/net_namespace.c:138
 setup_net+0x331/0xa30 net/core/net_namespace.c:332
 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:476
 create_new_namespaces+0x3a8/0x660 kernel/nsproxy.c:110
 copy_namespaces+0x1cc/0x220 kernel/nsproxy.c:178
 copy_process+0x1161/0x3230 kernel/fork.c:2358
 kernel_clone+0x233/0x960 kernel/fork.c:2744
 __do_sys_clone kernel/fork.c:2870 [inline]
 __se_sys_clone kernel/fork.c:2854 [inline]
 __x64_sys_clone+0x198/0x210 kernel/fork.c:2854
 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f207a730159
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:00007f2079188fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f207a9b7fa0 RCX: 00007f207a730159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000c0126080
RBP: 00007f207a7c706b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f207a9b8038 R14: 00007f207a9b7fa0 R15: 00007ffe7cf839f8
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 199 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:206
Code: d0 a5 98 7e 65 8b 15 d1 a5 98 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 5c 0b 00 00 00 74 2c 8b 91 38 0b 00 00 <83> fa 02 75 21 48 8b 91 40 0b 00 00 48 8b 32 48 8d 7e 01 8b 89 3c
RSP: 0018:ffffc90000a27850 EFLAGS: 00000246
RAX: ffffffff815f77df RBX: 0000000000000001 RCX: ffff88811c6fcf00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000a27850 R08: ffff8881f7138e97 R09: 1ffff1103ee271d2
R10: dffffc0000000000 R11: ffffed103ee271d3 R12: ffff8881f7138e80
R13: 1ffff1103ee07af9 R14: 0000000000000000 R15: ffff8881f703d7c8
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd461a31000 CR3: 000000000660f000 CR4: 00000000003506a0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:440 [inline]
 smp_call_function_many_cond+0x8cf/0x9e0 kernel/smp.c:969
 on_each_cpu_cond_mask+0x43/0x80 kernel/smp.c:1134
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1442 [inline]
 text_poke_bp_batch+0x1d4/0x600 arch/x86/kernel/alternative.c:1642
 text_poke_flush arch/x86/kernel/alternative.c:1833 [inline]
 text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1840
 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:146
 __jump_label_update+0x38f/0x3b0 kernel/jump_label.c:459
 jump_label_update+0x39b/0x450 kernel/jump_label.c:830
 static_key_enable_cpuslocked+0x126/0x240 kernel/jump_label.c:177
 static_key_enable+0x1a/0x30 kernel/jump_label.c:190
 toggle_allocation_gate+0xba/0x440 mm/kfence/core.c:783
 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328
 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475
 kthread+0x3f5/0x4f0 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>