syzbot

watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.1.992:9973]
Modules linked in:
irq event stamp: 14459223
hardirqs last  enabled at (14459222): [<ffffffff8badef2e>] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242
hardirqs last disabled at (14459223): [<ffffffff8badd93e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last  enabled at (14409894): [<ffffffff8188026f>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last  enabled at (14409894): [<ffffffff8188026f>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last  enabled at (14409894): [<ffffffff8188026f>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
softirqs last disabled at (14409897): [<ffffffff8188026f>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (14409897): [<ffffffff8188026f>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (14409897): [<ffffffff8188026f>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
CPU: 0 UID: 0 PID: 9973 Comm: syz.1.992 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x27/0x90 kernel/kcov.c:321
Code: 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 68 2d 56 11 65 8b 15 89 2d 56 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 <83> b9 94 16 00 00 00 74 4e 8b 91 70 16 00 00 83 fa 03 75 43 48 8b
RSP: 0018:ffffc900000078d8 EFLAGS: 00000246
RAX: ffffffff8975036a RBX: ffff888058777280 RCX: ffff88807cce0000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8880587772fe R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88802b1a1140 R15: 0000000000000000
FS:  00007fbb958636c0(0000) GS:ffff888125463000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb95821d58 CR3: 000000007929c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __skb_dst_copy include/net/dst.h:291 [inline]
 skb_dst_copy include/net/dst.h:299 [inline]
 __copy_skb_header+0xca/0x4a0 net/core/skbuff.c:1566
 __skb_clone+0x63/0x7a0 net/core/skbuff.c:1617
 skb_clone+0x246/0x3a0 net/core/skbuff.c:2127
 hsr_forward_do net/hsr/hsr_forward.c:-1 [inline]
 hsr_forward_skb+0x1028/0x2860 net/hsr/hsr_forward.c:743
 send_hsr_supervision_frame+0x731/0xcb0 net/hsr/hsr_device.c:364
 hsr_announce+0x1db/0x370 net/hsr/hsr_device.c:421
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x245/0x920 kernel/sched/core.c:5152
Code: 00 00 48 85 db 0f 85 e8 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 49 83 c4 48 4c 89 e7 e8 85 89 1b 0a e8 b0 8e 38 00 fb 4c 8b 65 c0 <49> 8d bc 24 70 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900038b7738 EFLAGS: 00000202
RAX: 000000000014b001 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000007 RSI: ffffffff8def4b84 RDI: ffffffff8c27b400
RBP: ffffc900038b7790 R08: ffffffff90118bb7 R09: 1ffffffff2023176
R10: dffffc0000000000 R11: fffffbfff2023177 R12: ffff88807cce0000
R13: dffffc0000000000 R14: ffff888026af5b80 R15: ffff8880b863b918
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15e5/0x52d0 kernel/sched/core.c:6908
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7235
 irqentry_exit+0x599/0x620 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:235
Code: 70 16 00 00 83 fa 02 75 21 48 8b 91 78 16 00 00 48 8b 32 48 8d 7e 01 8b 89 74 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <e9> 8f 2a eb 09 cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc900038b7ad8 EFLAGS: 00000287
RAX: ffffffff81fbe669 RBX: 1ffffffff1d04698 RCX: 0000000000080000
RDX: ffffc9001b5f9000 RSI: 000000000001b9b1 RDI: 000000000001b9b2
RBP: 0000000000000000 R08: ffff88802b715bab R09: 1ffff110056e2b75
R10: dffffc0000000000 R11: ffffed10056e2b76 R12: ffff88801d6e8098
R13: 0000000000000000 R14: ffffffff8e8234c0 R15: dffffc0000000000
 perf_try_init_event+0x299/0x870 kernel/events/core.c:13046
 perf_init_event kernel/events/core.c:13130 [inline]
 perf_event_alloc+0x1444/0x2e30 kernel/events/core.c:13405
 __do_sys_perf_event_open kernel/events/core.c:13927 [inline]
 __se_sys_perf_event_open+0x7a9/0x1d60 kernel/events/core.c:13808
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb9499c799
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:00007fbb95863028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fbb94c15fa0 RCX: 00007fbb9499c799
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007fbb94a32c99 R08: 000000000000000a R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbb94c16038 R14: 00007fbb94c15fa0 R15: 00007ffc63682a98
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7558 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xce5/0x12c0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 24 e6 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 cf e1 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 b3 e1
RSP: 0018:ffffc900035c7720 EFLAGS: 00000293
RAX: ffffffff81b9bbfd RBX: 1ffff110170c8515 RCX: ffff88807cbb8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900035c7860 R08: ffffffff90118bb7 R09: 1ffffffff2023176
R10: dffffc0000000000 R11: fffffbfff2023177 R12: ffff8880b86428a8
R13: dffffc0000000000 R14: ffff8880b873bf80 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125563000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558a7b5e38 CR3: 000000000e54c000 CR4: 00000000003526f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2761 [inline]
 smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2971
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
 static_key_disable+0x1a/0x20 kernel/jump_label.c:248
 toggle_allocation_gate+0x1fe/0x290 mm/kfence/core.c:907
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>