watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.4.4507:21791] Modules linked in: irq event stamp: 14129913 hardirqs last enabled at (14129912): [<ffffffff8baebf2e>] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242 hardirqs last disabled at (14129913): [<ffffffff8baea93e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (10915842): [<ffffffff8188041f>] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (10915842): [<ffffffff8188041f>] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (10915842): [<ffffffff8188041f>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 softirqs last disabled at (10915845): [<ffffffff8188041f>] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (10915845): [<ffffffff8188041f>] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (10915845): [<ffffffff8188041f>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 CPU: 0 UID: 0 PID: 21791 Comm: syz.4.4507 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__srcu_check_read_flavor+0x87/0x250 kernel/rcu/srcutree.c:798 Code: 3c 28 00 74 08 4c 89 e7 e8 e6 b1 85 00 49 8b 2c 24 4c 89 7c 24 08 4d 8d 24 2f 49 83 c4 20 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 0a 01 00 00 41 8b 04 24 49 83 c6 10 4d 89 f7 49 c1 ef RSP: 0018:ffffc90000007068 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000102 RDX: ffffffff90a6eb01 RSI: 0000000000000004 RDI: ffffffff8e7bd4c0 RBP: ffffffff931cc180 R08: ffffc90000007247 R09: 0000000000000000 R10: ffffc90000007238 R11: fffff52000000e49 R12: ffff8880b86291a0 R13: dffffc0000000000 R14: ffffffff8e7bd4c0 R15: ffff88812545d000 FS: 00007f483b8ef6c0(0000) GS:ffff88812545d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f483b8add58 CR3: 0000000061a1e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: <IRQ> srcu_check_read_flavor include/linux/srcutree.h:373 [inline] srcu_read_lock_fast_notrace include/linux/srcu.h:385 [inline] class_srcu_fast_notrace_constructor include/linux/srcu.h:634 [inline] __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x36c/0x3d0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484 alloc_frozen_pages_noprof mm/mempolicy.c:2555 [inline] alloc_pages_noprof+0xa8/0x190 mm/mempolicy.c:2575 skb_page_frag_refill+0x179/0x310 net/core/sock.c:3146 add_recvbuf_mergeable drivers/net/virtio_net.c:2782 [inline] try_fill_recv+0xa31/0x20f0 drivers/net/virtio_net.c:2837 virtnet_receive drivers/net/virtio_net.c:2998 [inline] virtnet_poll+0x237c/0x2f90 drivers/net/virtio_net.c:3083 __napi_poll+0xae/0x340 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7912 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:schedule_debug kernel/sched/core.c:5857 [inline] RIP: 0010:__schedule+0x18d/0x52d0 kernel/sched/core.c:6786 Code: 74 08 48 89 df e8 23 5e 80 f6 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 0a 5e 80 f6 48 81 3b 9d 6e ac 57 <0f> 85 8a 1a 00 00 45 85 ed 7f 4c 48 8b 44 24 10 48 8d 58 18 48 89 RSP: 0018:ffffc90003427440 EFLAGS: 00000246 RAX: 1ffff92000684000 RBX: ffffc90003420000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8c27c8e0 RDI: ffffffff8c27c8a0 RBP: ffffc90003427640 R08: ffffffff9011b2b7 R09: 1ffffffff2023656 R10: dffffc0000000000 R11: fffffbfff2023657 R12: ffff88812545d000 R13: 0000000000000001 R14: dffffc0000000000 R15: 1ffff110170c75c3 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 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:orc_find arch/x86/kernel/unwind_orc.c:228 [inline] RIP: 0010:unwind_next_frame+0x214/0x23c0 arch/x86/kernel/unwind_orc.c:510 Code: ef 08 8b 15 1e 9d a4 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 80 c0 52 91 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 25 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d RSP: 0018:ffffc90003427778 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000080000000 RDX: 00000000000ab27c RSI: ffffffff8c27c8e0 RDI: ffffffff8c27c8a0 RBP: dffffc0000000000 R08: ffffffff81767e95 R09: ffffffff8e75e5e0 R10: ffffc900034278a8 R11: fffff52000684f21 R12: ffffffff8176a786 R13: ffffffff91549b1c R14: ffffc900034278a8 R15: 00000000000076a7 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873 lsm_file_alloc security/security.c:169 [inline] security_file_alloc+0x34/0x310 security/security.c:2380 init_file+0x90/0x2b0 fs/file_table.c:159 alloc_empty_file+0x6e/0x1d0 fs/file_table.c:241 alloc_file fs/file_table.c:355 [inline] alloc_file_pseudo+0x155/0x240 fs/file_table.c:384 sock_alloc_file+0xb8/0x2e0 net/socket.c:483 __sys_socketpair+0x386/0x560 net/socket.c:1841 __do_sys_socketpair net/socket.c:1863 [inline] __se_sys_socketpair net/socket.c:1860 [inline] __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1860 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: 0033:0x7f483a99c799 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:00007f483b8ef028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f483ac15fa0 RCX: 00007f483a99c799 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00007f483aa32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f483ac16038 R14: 00007f483ac15fa0 R15: 00007ffebf997f18 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18277 Comm: kworker/u8:14 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 b4 e6 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 5f e2 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 43 e2 RSP: 0018:ffffc90004107700 EFLAGS: 00000293 RAX: ffffffff81b9bfed RBX: 1ffff110170c8525 RCX: ffff88802d695b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004107840 R08: ffffffff9011b2b7 R09: 1ffffffff2023656 R10: dffffc0000000000 R11: fffffbfff2023657 R12: ffff8880b8642928 R13: dffffc0000000000 R14: ffff8880b873c000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812555d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcb4e7eb4b8 CR3: 000000000e54c000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 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:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 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>