rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=2f64/0/0x1 softirq=13212/13212 fqs=1
	(t=10501 jiffies g=16221 q=300 ncpus=2)
rcu: rcu_preempt kthread starved for 10500 jiffies! g16221 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:26784 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5181 Comm: syz.3.226 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:119 [inline]
RIP: 0010:lock_acquire+0x11c/0x490 kernel/locking/lockdep.c:5638
Code: c0 64 a1 1f 8e 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 07 02 00 00 83 3d d5 aa bc 0c 00 0f 84 f1 00 00 00 65 8b 05 e4 82 9f 7e <85> c0 0f 85 2f 01 00 00 65 4c 8b 35 94 78 9f 7e 49 81 c6 dc 0a 00
RSP: 0018:ffffc900001e0a40 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 4f7a414a95cab100
RDX: 0000000000000000 RSI: ffffffff8adef380 RDI: ffffffff8adef340
RBP: ffffc900001e0b48 R08: dffffc0000000000 R09: fffffbfff1c3ed96
R10: fffffbfff1c3ed96 R11: 1ffffffff1c3ed95 R12: 0000000000000001
R13: 1ffff9200003c154 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f19a83bc6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000029b23000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 __lock_task_sighand+0x146/0x2d0 kernel/signal.c:1411
 lock_task_sighand include/linux/sched/signal.h:745 [inline]
 send_sigqueue+0x159/0x600 kernel/signal.c:1979
 posix_timer_event kernel/time/posix-timers.c:360 [inline]
 posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 3e 9d 41 f7 48 89 df e8 96 62 42 f7 e8 b1 54 65 f7 fb bf 01 00 00 00 <e8> 46 dd 35 f7 65 8b 05 c7 94 e0 75 85 c0 74 02 5b c3 e8 14 a6 de
RSP: 0018:ffffc9001c8bfb98 EFLAGS: 00000282
RAX: 4f7a414a95cab100 RBX: ffff888019ea6f00 RCX: 4f7a414a95cab100
RDX: dffffc0000000000 RSI: ffffffff8a8c0580 RDI: 0000000000000001
RBP: ffff888019ea7398 R08: dffffc0000000000 R09: ffffed10033d4de1
R10: ffffed10033d4de1 R11: 1ffff110033d4de0 R12: 1ffff110033d4e73
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x1163/0x1350 kernel/signal.c:2874
 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f19a758efc7
Code: ff ff 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
RSP: 002b:00007f19a83bc0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f19a77e5fa8 RCX: 00007f19a758efc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f19a77e5fa8
RBP: 00007f19a77e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f19a77e6038 R14: 00007ffdbbd671d0 R15: 00007ffdbbd672b8
 </TASK>
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 d7 47 af f7 e9 4c ff ff ff e8 ad 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 67 e4 64 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8c807d88 EFLAGS: 000002c6
RAX: dc673f7f35b9b400 RBX: ffffffff8a21bec7 RCX: dc673f7f35b9b400
RDX: 0000000000000001 RSI: ffffffff8a8c0580 RDI: ffffffff8adef3a0
RBP: ffffffff8c807ec0 R08: dffffc0000000000 R09: ffffed10171c6afa
R10: ffffed10171c6afa R11: 1ffff110171c6af9 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8c8bc740 R15: 1ffffffff1c3edd6
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000008030 CR3: 000000005c67a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1fc/0x570 kernel/sched/idle.c:303
 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
 rest_init+0x2dc/0x300 init/main.c:745
 arch_call_rest_init+0xa/0xa init/main.c:905
 start_kernel+0x490/0x539 init/main.c:1152
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>