syzbot

watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.8.3586:18935]
Modules linked in:
irq event stamp: 5133197
hardirqs last  enabled at (5133196): [<ffffffff8b793234>] irqentry_exit+0x74/0x90 kernel/entry/common.c:200
hardirqs last disabled at (5133197): [<ffffffff8b791e6e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050
softirqs last  enabled at (4868596): [<ffffffff8184f4da>] __do_softirq kernel/softirq.c:613 [inline]
softirqs last  enabled at (4868596): [<ffffffff8184f4da>] invoke_softirq kernel/softirq.c:453 [inline]
softirqs last  enabled at (4868596): [<ffffffff8184f4da>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
softirqs last disabled at (4868599): [<ffffffff8184f4da>] __do_softirq kernel/softirq.c:613 [inline]
softirqs last disabled at (4868599): [<ffffffff8184f4da>] invoke_softirq kernel/softirq.c:453 [inline]
softirqs last disabled at (4868599): [<ffffffff8184f4da>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
CPU: 0 UID: 0 PID: 18935 Comm: syz.8.3586 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x2a/0xe0 kernel/rcu/tree_plugin.h:435
Code: f3 0f 1e fa 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3c 25 08 40 a0 92 48 8d 9f 44 04 00 00 49 89 dc <49> c1 ec 03 43 0f b6 04 3c 84 c0 75 4f ff 0b 75 1d 4c 8d b7 48 04
RSP: 0018:ffffc90000006c30 EFLAGS: 00000286
RAX: 50167c98cf70e600 RBX: ffff88802724de44 RCX: 50167c98cf70e600
RDX: 0000000000000004 RSI: ffffffff8dba5b5c RDI: ffff88802724da00
RBP: ffffc90000006d70 R08: ffffc90000006bd7 R09: 0000000000000000
R10: ffffc90000006bc0 R11: fffff52000000d7b R12: ffff88802724de44
R13: 00000000ffffffe4 R14: 0000000000000001 R15: dffffc0000000000
FS:  00007f7c505716c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001100 CR3: 000000007f1ca000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:873 [inline]
 __perf_event_output kernel/events/core.c:8488 [inline]
 perf_event_output_forward+0x384/0x430 kernel/events/core.c:8497
 __perf_event_overflow+0x7cf/0xe10 kernel/events/core.c:10372
 perf_swevent_overflow kernel/events/core.c:10447 [inline]
 perf_swevent_event+0x2f4/0x5e0 kernel/events/core.c:-1
 perf_tp_event+0x4f6/0x1380 kernel/events/core.c:10992
 perf_trace_run_bpf_submit+0xee/0x170 kernel/events/core.c:10916
 do_perf_trace_lock include/trace/events/lock.h:50 [inline]
 perf_trace_lock+0x2f8/0x3b0 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+0x3b2/0x3e0 kernel/locking/lockdep.c:5879
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x18f/0x400 mm/slub.c:4782
 kfree_skb_reason include/linux/skbuff.h:1275 [inline]
 kfree_skb include/linux/skbuff.h:1284 [inline]
 hsr_forward_skb+0x1ac6/0x2860 net/hsr/hsr_forward.c:-1
 send_hsr_supervision_frame+0x612/0xb30 net/hsr/hsr_device.c:358
 hsr_announce+0x1d5/0x360 net/hsr/hsr_device.c:415
 call_timer_fn+0x17b/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:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5225
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 2f a7 ea 09 e8 5a 3f 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900032277d8 EFLAGS: 00000286
RAX: 50167c98cf70e600 RBX: 0000000000000000 RCX: 50167c98cf70e600
RDX: 0000000000000000 RSI: ffffffff8d9b68b0 RDI: ffffffff8be33280
RBP: ffffc90003227830 R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6
R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: ffff88802724da00
R13: dffffc0000000000 R14: ffff888052113c00 R15: ffff8880b863ab58
 context_switch kernel/sched/core.c:5360 [inline]
 __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6961
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 ab 62 b7 f5 cc
RSP: 0018:ffffc90003227bd8 EFLAGS: 00000297
RAX: ffffffff81b3d9d3 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff88802724da00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003227cf0 R08: ffff88807a2986c3 R09: 1ffff1100f4530d8
R10: dffffc0000000000 R11: ffffed100f4530d9 R12: 00000000000f4240
R13: 0000000000000000 R14: ffff88807a2986c0 R15: 00000000ffffffff
 futex_wake+0x1a3/0x560 kernel/futex/waitwake.c:175
 do_futex+0x395/0x420 kernel/futex/syscalls.c:107
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:160
 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: 0033:0x7f7c4f78ebe9
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:00007f7c505710e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f7c4f9c5fa8 RCX: 00007f7c4f78ebe9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7c4f9c5fac
RBP: 00007f7c4f9c5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c4f9c6038 R14: 00007ffd4560d380 R15: 00007ffd4560d468
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12042 Comm: kworker/u8:24 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 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 45 5e 0b 00 eb e4 44
RSP: 0018:ffffc900054b7660 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170c8341 RCX: ffff88802bd6bc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900054b77e0 R08: ffffffff8fa37e37 R09: 1ffffffff1f46fc6
R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: ffff8880b8641a08
R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd1b8fc6038 CR3: 000000000df36000 CR4: 00000000003526f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
 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:850
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>