watchdog: BUG: soft lockup - CPU#1 stuck for 134s! [syz.5.624:8545] Modules linked in: irq event stamp: 15937647 hardirqs last enabled at (15937646): [] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219 hardirqs last disabled at (15937647): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (15826422): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (15826422): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (15826422): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 softirqs last disabled at (15826425): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (15826425): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (15826425): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 CPU: 1 UID: 0 PID: 8545 Comm: syz.5.624 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67 Code: b3 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 58 0b d8 09 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a085f0 EFLAGS: 00000202 RAX: ffffffff821bec78 RBX: ffffc9000ba17568 RCX: 1ffff92000141001 RDX: ffffffff901f74e0 RSI: 0000000000000002 RDI: ffffc9000ba17568 RBP: 1ffff920001410da R08: 000000000000000e R09: ffffffff8df41cc0 R10: ffffc90000a081c8 R11: fffff5200014103b R12: ffffc9000ba18000 R13: 1ffff920001410db R14: ffffc90000a086c8 R15: ffffc9000ba10000 FS: 00007f40064b86c0(0000) GS:ffff8881261b1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faad229e000 CR3: 000000002c93a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0xc3c/0x2390 arch/x86/kernel/unwind_orc.c:585 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:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] 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:6663 [inline] kmem_cache_free+0x197/0x620 mm/slub.c:6774 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1428 mac80211_hwsim_beacon_tx+0x3e8/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2365 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__percpu_counter_sum+0x1c5/0x1e0 lib/percpu_counter.c:184 Code: c1 7c d6 48 89 ef e8 8a f9 65 fd eb cc e8 a3 15 00 fd eb 05 e8 9c 15 00 fd 48 8b 7c 24 08 48 8b 34 24 e8 be a7 8a 06 4c 89 f8 <48> 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 72 RSP: 0018:ffffc9000ba17028 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff1100aaa7edc RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8d76bd39 RDI: 00000000ffffffff RBP: 0000000000000000 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: ffff88805553f6e0 R13: 0000000000000002 R14: ffffffff8d98bdd8 R15: 0000000000000000 percpu_counter_sum include/linux/percpu_counter.h:105 [inline] check_mm kernel/fork.c:586 [inline] __mmdrop+0x1de/0x750 kernel/fork.c:687 mmdrop include/linux/sched/mm.h:55 [inline] mmdrop_sched include/linux/sched/mm.h:83 [inline] mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline] finish_task_switch+0x44b/0x940 kernel/sched/core.c:5139 context_switch kernel/sched/core.c:5259 [inline] __schedule+0x14c4/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:get_task_policy mm/mempolicy.c:341 [inline] RIP: 0010:alloc_frozen_pages_noprof+0x61/0x170 mm/mempolicy.c:2485 Code: b5 3a 9d ff 45 09 f7 74 0e e8 6b 36 9d ff 48 c7 c2 e0 e9 05 8e eb 43 49 bf 00 00 00 00 00 fc ff df 65 4c 8b 34 25 08 f0 76 92 <49> 81 c6 28 15 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c RSP: 0018:ffffc9000ba17508 EFLAGS: 00000246 RAX: ffffffff822413eb RBX: 0000000000000003 RCX: 0000000000000000 RDX: ffff88801f768000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000004429c0 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e R10: dffffc0000000000 R11: ffffffff81689b10 R12: 0000000000006968 R13: ffffffff81d4302f R14: ffff88801f768000 R15: dffffc0000000000 ___kmalloc_large_node+0x4e/0x100 mm/slub.c:5593 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:5624 __do_kmalloc_node mm/slub.c:5640 [inline] __kvmalloc_node_noprof+0x6e/0x910 mm/slub.c:7128 bpf_check+0xef/0x1c300 kernel/bpf/verifier.c:25126 bpf_prog_load+0x13ba/0x1a10 kernel/bpf/syscall.c:3088 __sys_bpf+0x507/0x860 kernel/bpf/syscall.c:6164 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline] __se_sys_bpf kernel/bpf/syscall.c:6272 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6272 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: 0033:0x7f400558f749 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:00007f40064b8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f40057e6090 RCX: 00007f400558f749 RDX: 0000000000000094 RSI: 0000200000001140 RDI: 0000000000000005 RBP: 00007f4005613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f40057e6128 R14: 00007f40057e6090 R15: 00007ffc5a72aba8 Sending NMI from CPU 1 to CPUs 0: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8552 Comm: kworker/u8:18 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:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 0e 1c ab fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ff ff 10 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 1a fb 35 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000007398 EFLAGS: 00000006 RAX: 1ffffffff336ee05 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc90000007570 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff85162e00 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff99b77240 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881260b1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f61685e6038 CR3: 000000000dd3a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: serial_port_in include/linux/serial_core.h:806 [inline] serial8250_console_write+0x584/0x1ba0 drivers/tty/serial/8250/8250_port.c:3306 console_emit_next_record kernel/printk/printk.c:3129 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426 _printk+0xcf/0x120 kernel/printk/printk.c:2451 print_other_cpu_stall+0x189/0x1340 kernel/rcu/tree_stall.h:656 check_cpu_stall kernel/rcu/tree_stall.h:856 [inline] rcu_pending kernel/rcu/tree.c:3667 [inline] rcu_sched_clock_irq+0xac1/0x1280 kernel/rcu/tree.c:2704 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2474 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x3e9/0x710 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 4a 94 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 f5 8f 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 d9 8f RSP: 0018:ffffc9000ba2f620 EFLAGS: 00000293 RAX: ffffffff81b5ba87 RBX: 1ffff11017128101 RCX: ffff88802edfbd00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000ba2f7a0 R08: ffffffff8f805a77 R09: 1ffffffff1f00b4e R10: dffffc0000000000 R11: fffffbfff1f00b4f R12: ffff8880b8940808 R13: dffffc0000000000 R14: ffff8880b883b9c0 R15: 0000000000000001 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:854 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