rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=4fcc/1/0x4000000000000000 softirq=15298/15313 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5957/1:b..l
rcu: 	(detected by 1, t=10517 jiffies, g=9285, q=902 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6093 Comm: kworker/0:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_power_efficient gc_worker
RIP: 0010:_raw_spin_unlock_irqrestore+0xe/0x80 kernel/locking/spinlock.c:193
Code: 5b e9 46 4d 00 00 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 f5 53 48 8b 74 24 10 <48> 89 fb 48 83 c7 18 e8 26 48 35 f6 48 89 df e8 0e 9c 35 f6 f7 c5
RSP: 0000:ffffc90000007d08 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff88805ad4d2a0 RCX: 1ffff1100b5a9a56
RDX: ffffffff8b903340 RSI: ffffffff84acb8fc RDI: ffffffff9ad59738
RBP: 0000000000000006 R08: 0000000000000001 R09: fffff52000000f92
R10: 0000000000000006 R11: ffffffff9ad59738 R12: 0000000000000002
R13: ffff888030c66340 R14: dffffc0000000000 R15: 1ffff92000000fa8
FS:  0000000000000000(0000) GS:ffff888124a05000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b1a2708fe8 CR3: 000000005ddd9000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 debug_object_activate+0x2ec/0x4c0 lib/debugobjects.c:836
 debug_hrtimer_activate kernel/time/hrtimer.c:438 [inline]
 debug_activate kernel/time/hrtimer.c:477 [inline]
 enqueue_hrtimer+0x23/0x3b0 kernel/time/hrtimer.c:1081
 __run_hrtimer kernel/time/hrtimer.c:1794 [inline]
 __hrtimer_run_queues+0x8ff/0xad0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x66/0x70 kernel/kcov.c:235
Code: 82 58 16 00 00 83 f8 02 75 20 48 8b 8a 60 16 00 00 8b 92 5c 16 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 <e9> 55 df a6 09 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc900036b7b40 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff897fa52c
RDX: ffff888025bdc900 RSI: ffffffff897fab1e RDI: 0000000000000005
RBP: ffffffff9af903ec R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888023e00000
R13: 0000000000026635 R14: dffffc0000000000 R15: 0000000000001770
 rcu_read_unlock include/linux/rcupdate.h:895 [inline]
 gc_worker+0x96e/0x16e0 net/netfilter/nf_conntrack_core.c:1617
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:udevd           state:R  running task     stack:25592 pid:5957  tgid:5957  ppid:5185   task_flags:0x400140 flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 wp_page_copy mm/memory.c:3781 [inline]
 do_wp_page+0x186d/0x52b0 mm/memory.c:4141
 handle_pte_fault mm/memory.c:6211 [inline]
 __handle_mm_fault+0x1ae3/0x2aa0 mm/memory.c:6336
 handle_mm_fault+0x589/0xd10 mm/memory.c:6505
 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f11450b5db7
RSP: 002b:00007ffcacdc3750 EFLAGS: 00010202
RAX: 0000000000006010 RBX: 00000000000001f0 RCX: 000055b1a2708fe0
RDX: 0000000000006010 RSI: 000055b1a2702fd0 RDI: 00007f11451f1ac0
RBP: 00007f11451f1ac0 R08: 00000000000001f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055b1a2702fd0
R13: 00007f11451f1ac0 R14: 00000000000001f0 R15: 00007f11451f1ac0
 </TASK>
rcu: rcu_preempt kthread starved for 10517 jiffies! g9285 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:29120 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 2938 Comm: kworker/u8:6 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:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:246
Code: a6 09 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 a7 ce e4 11 <65> 8b 05 b8 ce e4 11 a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00
RSP: 0018:ffffc9000bc87870 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8880b8442840 RCX: ffffffff81b0db51
RDX: ffff888030962480 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffed1017088509 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b1a270ebe0 CR3: 000000000e182000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0xe21/0x1600 kernel/smp.c:877
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2713 [inline]
 smp_text_poke_batch_finish+0x5ad/0xdb0 arch/x86/kernel/alternative.c:2985
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x376/0x550 kernel/jump_label.c:919
 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:852 [inline]
 toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:844
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>