watchdog: BUG: soft lockup - CPU#0 stuck for 122s! [syz.2.768:8020] Modules linked in: irq event stamp: 11957285 hardirqs last enabled at (11957284): [] asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 hardirqs last disabled at (11957285): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1088 softirqs last enabled at (34174): [] __do_softirq kernel/softirq.c:612 [inline] softirqs last enabled at (34174): [] invoke_softirq kernel/softirq.c:452 [inline] softirqs last enabled at (34174): [] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 softirqs last disabled at (34177): [] __do_softirq kernel/softirq.c:612 [inline] softirqs last disabled at (34177): [] invoke_softirq kernel/softirq.c:452 [inline] softirqs last disabled at (34177): [] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 CPU: 0 PID: 8020 Comm: syz.2.768 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] RIP: 0010:unwind_next_frame+0xe7d/0x2970 arch/x86/kernel/unwind_orc.c:585 Code: 03 0f 84 f6 00 00 00 41 83 fe 02 0f 85 8c 02 00 00 48 89 9c 24 80 00 00 00 49 8d 5c 24 08 49 89 dc 49 c1 ec 03 43 80 3c 2c 00 <74> 08 48 89 df e8 69 25 a4 00 48 89 5c 24 70 4c 89 7c 24 38 48 89 RSP: 0000:ffffc900000073d8 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffffc900000074b0 RCX: 0000000000000003 RDX: ffffffff813b4606 RSI: ffffffff8cfa0870 RDI: 0000000000000002 RBP: ffffc900000074f8 R08: ffff888044411e00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: 1ffff92000000e96 R13: dffffc0000000000 R14: 0000000000000002 R15: ffffffff8f1a4224 FS: 00007fe3852db6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000004d0a0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 skb_kfree_head net/core/skbuff.c:946 [inline] skb_free_head net/core/skbuff.c:958 [inline] skb_release_data+0x5dc/0x7b0 net/core/skbuff.c:988 skb_release_all net/core/skbuff.c:1054 [inline] __kfree_skb+0x57/0x70 net/core/skbuff.c:1068 tcp_write_queue_purge+0x143/0x2f0 net/ipv4/tcp.c:3007 tcp_done_with_error+0x43/0xc0 net/ipv4/tcp_input.c:4446 tcp_write_err net/ipv4/tcp_timer.c:72 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:281 [inline] tcp_retransmit_timer+0x1728/0x3020 net/ipv4/tcp_timer.c:576 tcp_write_timer+0x12a/0x280 net/ipv4/tcp_timer.c:709 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:exit_to_user_mode_loop+0x40/0x110 kernel/entry/common.c:164 Code: fb eb 1d e8 72 92 14 09 65 48 8b 05 3a d8 8f 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 c4 00 00 00 e8 a5 c0 19 00 fb 41 f6 c6 08 <74> 05 e8 e9 bd 1c 09 41 f7 c6 00 10 00 00 74 08 48 89 df e8 d8 b1 RSP: 0000:ffffc90003487f10 EFLAGS: 00000202 RAX: 34e2d95990f6ef00 RBX: ffffc90003487f58 RCX: 34e2d95990f6ef00 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9c20 RBP: 0000000000000000 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd R10: dffffc0000000000 R11: fffffbfff1d16cce R12: 0000000000000000 R13: 0000000000000000 R14: 000000000000000a R15: ffff888044411e00 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0033:0x7fe384263336 Code: 00 00 00 00 45 31 c0 31 c9 ba 80 00 00 00 48 89 de bf ca 00 00 00 31 c0 e8 17 9b 13 00 8b 03 85 c0 74 e1 c7 45 08 00 00 00 00 <45> 84 e4 74 31 80 3d a3 23 ee 00 00 74 28 80 3d 88 23 ee 00 00 0f RSP: 002b:00007fe3852db0f0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 00007fe384615fa8 RCX: 00007fe38439ce59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe384615fa8 RBP: 00007fe384615fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe384616038 R14: 00007ffea778bc60 R15: 00007ffea778bd48 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8022 Comm: syz.3.769 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:unwind_next_frame+0x858/0x2970 arch/x86/kernel/unwind_orc.c:517 Code: 9e eb 4b 00 49 89 df e9 b1 05 00 00 41 83 fe 04 0f 84 6c 01 00 00 41 83 fe 05 0f 85 f6 02 00 00 e8 7d eb 4b 00 48 8b 44 24 68 <42> 80 3c 28 00 48 8b 5c 24 60 74 08 48 89 df e8 84 2b a4 00 48 8b RSP: 0018:ffffc900001efc10 EFLAGS: 00000006 RAX: 1ffff9200003dfaf RBX: ffffffff8f194a22 RCX: ffff888029703c00 RDX: 0000000000010100 RSI: ffffffff8cfa0820 RDI: 0000000000000005 RBP: ffffc900001efd90 R08: ffff888029703c00 R09: 0000000000000008 R10: 0000000000000009 R11: 0000000000010100 R12: ffffc900001efd40 R13: dffffc0000000000 R14: 0000000000000005 R15: ffffffff8f194a26 FS: 00007f4e473ab6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f53b6357f70 CR3: 00000000396ec000 CR4: 00000000003506e0 Call Trace: perf_callchain_kernel+0x42e/0x690 arch/x86/events/core.c:2780 get_perf_callchain+0x231/0x510 kernel/events/callchain.c:204 perf_callchain kernel/events/core.c:7742 [inline] perf_sample_save_callchain include/linux/perf_event.h:1232 [inline] perf_prepare_sample+0x3c7/0x1df0 kernel/events/core.c:7786 __perf_event_output kernel/events/core.c:7974 [inline] perf_event_output_forward+0x187/0x3e0 kernel/events/core.c:7995 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_event_overflow kernel/events/core.c:9741 [inline] perf_swevent_hrtimer+0x439/0x610 kernel/events/core.c:11230 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x4e1/0xc40 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1880 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_release+0x594/0x8c0 kernel/locking/lockdep.c:5778 Code: 00 00 00 f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 2f 04 f8 75 70 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 43 c7 44 2f 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc900001f0740 EFLAGS: 00000206 RAX: 0000000000000001 RBX: cafa494bb340dd55 RCX: 917ad28fed07d600 RDX: 0000000000000004 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9c20 RBP: ffffc900001f0850 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd R10: dffffc0000000000 R11: fffffbfff1d16cce R12: ffff888029704780 R13: dffffc0000000000 R14: ffff8880297046d0 R15: 1ffff9200003e0f4 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 napi_frag_unref include/linux/skbuff.h:3539 [inline] skb_release_data+0x3a9/0x7b0 net/core/skbuff.c:982 skb_release_all net/core/skbuff.c:1054 [inline] __kfree_skb+0x57/0x70 net/core/skbuff.c:1068 tcp_write_queue_purge+0x143/0x2f0 net/ipv4/tcp.c:3007 tcp_done_with_error+0x43/0xc0 net/ipv4/tcp_input.c:4446 tcp_write_err net/ipv4/tcp_timer.c:72 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:281 [inline] tcp_retransmit_timer+0x1728/0x3020 net/ipv4/tcp_timer.c:576 tcp_write_timer+0x12a/0x280 net/ipv4/tcp_timer.c:709 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010 Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 a1 ea cb f6 e8 4c fd fc f6 fb bf 01 00 00 00 f1 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f RSP: 0018:ffffc90003307880 EFLAGS: 00000282 RAX: 917ad28fed07d600 RBX: 0000000000000000 RCX: 917ad28fed07d600 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc90003307920 R08: ffffffff911cd607 R09: 1ffffffff2239ac0 R10: dffffc0000000000 R11: fffffbfff2239ac1 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000660f10 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc900033079e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 917ad28fed07d600 RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9c20 RBP: ffffc90003307b00 R08: dffffc0000000000 R09: 1ffffffff2239aa0 R10: dffffc0000000000 R11: fffffbfff2239aa1 R12: 1ffff92000660f48 R13: ffffffff8d132160 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] __fget_files+0x45/0x4b0 fs/file.c:891 __fget fs/file.c:900 [inline] __fget_light fs/file.c:1000 [inline] __fdget+0x173/0x210 fs/file.c:1008 fdget include/linux/file.h:64 [inline] __bpf_prog_get kernel/bpf/syscall.c:2382 [inline] bpf_prog_get+0x1b/0x140 kernel/bpf/syscall.c:2401 _perf_ioctl kernel/events/core.c:6012 [inline] perf_ioctl+0x639/0x24a0 kernel/events/core.c:6076 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4e4659ce59 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:00007f4e473ab028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4e46815fa0 RCX: 00007f4e4659ce59 RDX: ffffffffffffffff RSI: 0000000040042408 RDI: 0000000000000003 RBP: 00007f4e46632d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4e46816038 R14: 00007f4e46815fa0 R15: 00007ffed3197718