watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.4.164:6588] Modules linked in: irq event stamp: 6510259 hardirqs last enabled at (6510258): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:214 hardirqs last disabled at (6510259): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1052 softirqs last enabled at (0): [] rcu_lock_acquire include/linux/rcupdate.h:331 [inline] softirqs last enabled at (0): [] rcu_read_lock include/linux/rcupdate.h:841 [inline] softirqs last enabled at (0): [] copy_process+0x97f/0x3c00 kernel/fork.c:2051 softirqs last disabled at (631): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (631): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (631): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 CPU: 0 UID: 0 PID: 6588 Comm: syz.4.164 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 ab d3 8e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 53 5d 57 f6 65 8b 05 3c fd 11 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90000007980 EFLAGS: 00000206 RAX: 388ad439bd7eb400 RBX: 0000000000000a06 RCX: 388ad439bd7eb400 RDX: 0000000000000002 RSI: ffffffff8d512c0f RDI: 0000000000000001 RBP: ffffc90000007a00 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6 R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: dffffc0000000000 R13: ffff888027b8f9a0 R14: ffffffff99789ca0 R15: 1ffff92000000f30 FS: 00007fa19d1f66c0(0000) GS:ffff88812638a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31263fff CR3: 000000001d6f6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: debug_object_assert_init+0x20e/0x380 lib/debugobjects.c:1009 debug_timer_assert_init kernel/time/timer.c:803 [inline] debug_assert_init kernel/time/timer.c:848 [inline] __mod_timer+0x4a/0xf30 kernel/time/timer.c:1025 lapb_start_t1timer net/lapb/lapb_timer.c:44 [inline] lapb_t1timer_expiry+0x745/0xab0 net/lapb/lapb_timer.c:202 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:generic_exec_single+0x481/0x500 kernel/smp.c:453 Code: 75 11 e8 b2 7f 0b 00 48 85 db 75 16 e8 a8 7f 0b 00 eb 15 e8 a1 7f 0b 00 e8 fc cd 81 09 48 85 db 74 ea e8 92 7f 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c RSP: 0018:ffffc9001a25f9c0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff888024c1bc80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9001a25fa90 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6 R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: 1ffff9200344bf3c R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff9200344bf5d smp_call_function_single+0x351/0x590 kernel/smp.c:684 task_function_call kernel/events/core.c:121 [inline] perf_install_in_context+0x593/0x8f0 kernel/events/core.c:3107 __do_sys_perf_event_open kernel/events/core.c:13735 [inline] __se_sys_perf_event_open+0x193a/0x1d70 kernel/events/core.c:13377 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa19ef8eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa19d1f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fa19f1e5fa0 RCX: 00007fa19ef8eec9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180 RBP: 00007fa19f011f91 R08: 000000000000000a R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa19f1e6038 R14: 00007fa19f1e5fa0 R15: 00007ffdfc504fc8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 79 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217 Code: 5b e9 93 75 5a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 60 49 92 <65> 8b 15 b8 e0 8a 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc9000216f658 EFLAGS: 00000202 RAX: ffffffff81b3103b RBX: 1ffff11017108439 RCX: ffff88801cb01e40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000216f7e0 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6 R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: ffff8880b88421c8 R13: dffffc0000000000 R14: ffff8880b893b200 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812648a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37a54500ab CR3: 000000000db36000 CR4: 00000000003526f0 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xd4b/0x12d0 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:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:852 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245