watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.4.159:6566] Modules linked in: irq event stamp: 13761077 hardirqs last enabled at (13761076): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:200 hardirqs last disabled at (13761077): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050 softirqs last enabled at (3941786): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last enabled at (3941786): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last enabled at (3941786): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 softirqs last disabled at (3941789): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (3941789): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (3941789): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 CPU: 0 UID: 0 PID: 6566 Comm: syz.4.159 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:memset_orig+0x9b/0xb0 arch/x86/lib/memset_64.S:113 Code: c9 48 89 07 48 8d 7f 08 75 f5 83 e2 07 74 0a ff ca 88 07 48 8d 7f 01 75 f6 4c 89 d0 c3 cc cc cc cc 48 83 fa 07 76 e3 48 89 07 <49> c7 c0 08 00 00 00 4d 29 c8 4c 01 c7 4c 29 c2 e9 6e ff ff ff 90 RSP: 0018:ffffc90000007a78 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 000000000000002c RCX: 0000000000000000 RDX: 0000000000000008 RSI: 0000000000000000 RDI: ffffe8ffffc7430c RBP: 0000000000000000 R08: ffffe8ffffc74313 R09: 0000000000000004 R10: ffffe8ffffc7430c R11: fffff91ffff8e863 R12: ffffffff8dbe2d10 R13: dffffc0000000000 R14: ffffe8ffffc742e8 R15: ffffffff8dbe2d10 FS: 00007fc465c0f6c0(0000) GS:ffff888125c11000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c9502a6b0 CR3: 000000007f290000 CR4: 00000000003526f0 Call Trace: perf_trace_buf_alloc+0x1d5/0x2a0 kernel/trace/trace_event_perf.c:419 do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x18d/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] ieee80211_rx_napi+0x223/0x3d0 net/mac80211/rx.c:5447 ieee80211_rx include/net/mac80211.h:5210 [inline] ieee80211_handle_queued_frames+0xe8/0x1f0 net/mac80211/main.c:453 tasklet_action_common+0x36c/0x580 kernel/softirq.c:829 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217 Code: 5b e9 93 53 59 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 f0 a0 92 <65> 8b 15 78 2a e1 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc900057ff2f8 EFLAGS: 00000246 RAX: ffffffff81f024c4 RBX: 0000000000000000 RCX: ffff888027263c00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900057ff568 R08: ffffc900057ff397 R09: 0000000000000000 R10: ffffc900057ff388 R11: fffff52000affe73 R12: 0000000000000000 R13: ffffc900057ff388 R14: 0000000000000000 R15: dffffc0000000000 perf_tp_event+0x664/0x1380 kernel/events/core.c:11007 perf_trace_run_bpf_submit+0xee/0x170 kernel/events/core.c:10923 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:1169 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 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:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x18e/0x440 mm/slub.c:4894 find_get_pmu_context+0x7cd/0x890 kernel/events/core.c:5100 __do_sys_perf_event_open kernel/events/core.c:13628 [inline] __se_sys_perf_event_open+0xbfd/0x1d70 kernel/events/core.c:13364 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: 0033:0x7fc464d8eec9 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:00007fc465c0f038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fc464fe5fa0 RCX: 00007fc464d8eec9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007fc464e11f91 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc464fe6038 R14: 00007fc464fe5fa0 R15: 00007ffdf8174e78 Sending NMI from CPU 0 to CPUs 1: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6634 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 5e 7b 6f 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 4f a0 d3 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000a08438 EFLAGS: 00000006 RAX: 1ffffffff33bf205 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc90000a08610 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff855049f0 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff99df9420 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d11000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3d75917d60 CR3: 000000000df36000 CR4: 00000000003526f0 Call Trace: serial_port_in include/linux/serial_core.h:793 [inline] serial8250_console_write+0x584/0x1ba0 drivers/tty/serial/8250/8250_port.c:3360 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 print_other_cpu_stall+0x189/0x1340 kernel/rcu/tree_stall.h:656 check_cpu_stall kernel/rcu/tree_stall.h:857 [inline] rcu_pending kernel/rcu/tree.c:3671 [inline] rcu_sched_clock_irq+0xa47/0x11b0 kernel/rcu/tree.c:2706 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2473 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x39a/0x520 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x4dd/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5f 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 5f RSP: 0018:ffffc90005b07660 EFLAGS: 00000293 RAX: ffffffff81b4665b RBX: 1ffff110170c8341 RCX: ffff888029d20000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005b077e0 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6 R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: ffff8880b8641a08 R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245