syzbot

watchdog: BUG: soft lockup - CPU#0 stuck for 126s! [syz.7.5629:29228]
Modules linked in:
irq event stamp: 8706639
hardirqs last  enabled at (8706638): [<ffffffff8b5bbffd>] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219
hardirqs last disabled at (8706639): [<ffffffff8b5ba86e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last  enabled at (3141520): [<ffffffff81858cca>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last  enabled at (3141520): [<ffffffff81858cca>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last  enabled at (3141520): [<ffffffff81858cca>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
softirqs last disabled at (3141523): [<ffffffff81858cca>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (3141523): [<ffffffff81858cca>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (3141523): [<ffffffff81858cca>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
CPU: 0 UID: 0 PID: 29228 Comm: syz.7.5629 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:strlen+0x2e/0x70 lib/string.c:420
Code: 41 57 41 56 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
RSP: 0018:ffffc90000006b98 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffffff8b6c1080 RCX: ffff88801db59e80
RDX: ffffffff81f2471f RSI: ffffffff8df41a20 RDI: ffffffff8b6c1080
RBP: ffffc90000006ca8 R08: ffffc90000006c97 R09: 0000000000000000
R10: ffffc90000006c80 R11: fffff52000000d93 R12: 1ffff92000000d80
R13: ffffffff81f2471f R14: dffffc0000000000 R15: ffffffffffffffff
FS:  00007f68f49ee6c0(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555912b65c8 CR3: 000000005406a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __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+0xc2/0x3b0 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+0x389/0x3b0 kernel/locking/lockdep.c:5879
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 __perf_event_output kernel/events/core.c:8516 [inline]
 perf_event_output_forward+0x37f/0x430 kernel/events/core.c:8525
 __perf_event_overflow+0x845/0xe70 kernel/events/core.c:10461
 perf_swevent_overflow kernel/events/core.c:10536 [inline]
 perf_swevent_event+0x2f4/0x5e0 kernel/events/core.c:-1
 perf_tp_event+0x4f6/0x1380 kernel/events/core.c:11081
 perf_trace_run_bpf_submit+0xee/0x170 kernel/events/core.c:11005
 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+0x389/0x3b0 kernel/locking/lockdep.c:5879
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
 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:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6668 [inline]
 kmem_cache_free+0x197/0x620 mm/slub.c:6779
 packet_rcv+0x175/0x1730 net/packet/af_packet.c:2223
 __netif_receive_skb_one_core net/core/dev.c:6137 [inline]
 __netif_receive_skb+0x164/0x380 net/core/dev.c:6250
 process_backlog+0x622/0x1500 net/core/dev.c:6602
 __napi_poll+0xae/0x320 net/core/dev.c:7666
 napi_poll net/core/dev.c:7729 [inline]
 net_rx_action+0x672/0xe50 net/core/dev.c:7881
 handle_softirqs+0x27d/0x850 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: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:bytes_is_nonzero mm/kasan/generic.c:98 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x9f/0x2c0 mm/kasan/generic.c:200
Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 de 01 00 00 49 ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd
RSP: 0018:ffffc9000524f008 EFLAGS: 00000246
RAX: ffffffff81f24901 RBX: fffffffffffffff9 RCX: ffffffff81f2492c
RDX: 0000000000000001 RSI: 0000000000000038 RDI: ffffc9000524f0a0
RBP: 0000000000000000 R08: ffffc9000524f0d7 R09: 1ffff92000a49e1a
R10: dffffc0000000000 R11: fffff52000a49e14 R12: 0000000000000007
R13: 0000000000000000 R14: fffff52000a49e1b R15: 1ffff92000a49e14
 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84
 __perf_event_output kernel/events/core.c:8497 [inline]
 perf_event_output_forward+0x29c/0x430 kernel/events/core.c:8525
 __perf_event_overflow+0x845/0xe70 kernel/events/core.c:10461
 perf_swevent_overflow kernel/events/core.c:10536 [inline]
 perf_swevent_event+0x2f4/0x5e0 kernel/events/core.c:-1
 perf_tp_event+0x4f6/0x1380 kernel/events/core.c:11081
 perf_trace_run_bpf_submit+0xee/0x170 kernel/events/core.c:11005
 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+0x389/0x3b0 kernel/locking/lockdep.c:5879
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
 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:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 lsm_file_alloc security/security.c:169 [inline]
 security_file_alloc+0x34/0x330 security/security.c:2380
 init_file+0x93/0x2f0 fs/file_table.c:159
 alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241
 alloc_file fs/file_table.c:354 [inline]
 alloc_file_pseudo+0x13d/0x210 fs/file_table.c:383
 sock_alloc_file+0xb8/0x2e0 net/socket.c:483
 sock_map_fd net/socket.c:513 [inline]
 __sys_socket+0x13d/0x1b0 net/socket.c:1756
 __do_sys_socket net/socket.c:1761 [inline]
 __se_sys_socket net/socket.c:1759 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1759
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68f678f749
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:00007f68f49ee038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f68f69e5fa0 RCX: 00007f68f678f749
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000010
RBP: 00007f68f6813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68f69e6038 R14: 00007f68f69e5fa0 R15: 00007fff1dc88598
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6043 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_pc+0x5d/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 <c3> cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc900055c7618 EFLAGS: 00000293
RAX: ffffffff81b61c77 RBX: 1ffff110170c856d RCX: ffff888077271e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900055c77a0 R08: ffffffff8f821f77 R09: 1ffffffff1f043ee
R10: dffffc0000000000 R11: fffffbfff1f043ef R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe70f84e58 CR3: 000000000dd3a000 CR4: 00000000003526f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xce7/0x12b0 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+0x5f9/0x1130 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+0xad/0x240 mm/kfence/core.c:874
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>