syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (3 ticks this GP) idle=be74/1/0x4000000000000000 softirq=15622/15622 fqs=0
rcu: 	(detected by 0, t=10505 jiffies, g=9537, q=975 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5795 Comm: kworker/1:3 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:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0xd/0xc0 kernel/rcu/tree.c:751
Code: 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 65 ff 05 c3 9e 0f 12 <e8> ce 0d d5 09 48 c7 c3 e8 e9 b3 93 89 c5 83 f8 07 0f 87 82 00 00
RSP: 0018:ffffc90000a08dc8 EFLAGS: 00000003
RAX: 0000000000000001 RBX: ffff8880b8528458 RCX: ffffffff81aac4f1
RDX: 1ffff110046f4665 RSI: ffffffff81aacbdf RDI: ffff8880b8528458
RBP: 0000000000000046 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8880369a2ff0 R12: ffffffff81aacbdf
R13: 1883d42c1e8c8308 R14: ffff8880237a3300 R15: ffffffff8980ad60
FS:  0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c007275000 CR3: 00000000233ff000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x201/0x2d0 kernel/locking/lockdep.c:5879
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194
 __run_hrtimer kernel/time/hrtimer.c:1773 [inline]
 __hrtimer_run_queues+0x58f/0xc40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9f/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:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893
Code: 0f c1 05 48 01 19 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 dd b9 18 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc900030c7a90 EFLAGS: 00000206
RAX: 8d687a12d9182900 RBX: ffffffff8e3c96a0 RCX: ffffc900030c7a9c
RDX: 0000000000000002 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400
RBP: ffffffff9b0a38ac R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8880369a2ff0 R12: ffffffff89940a39
R13: 0000000000000206 R14: ffff8880369a24c0 R15: 0000000000000003
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 gc_worker+0x99e/0x16e0 net/netfilter/nf_conntrack_core.c:1617
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g9537 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=6105
rcu: rcu_preempt kthread starved for 10505 jiffies! g9537 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:29112 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 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+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>