rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (2 GPs behind) idle=3d6c/0/0x1 softirq=49167/49168 fqs=0
	(t=10500 jiffies g=73865 q=44 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g73865 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=43204
rcu: rcu_preempt kthread starved for 10500 jiffies! g73865 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 14309 Comm: syz.6.3270 Not tainted 6.1.142-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_acquire+0x88/0x490 kernel/locking/lockdep.c:5630
Code: 8c 48 c7 44 24 70 d0 e9 62 81 4c 8d 6c 24 60 49 c1 ed 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4b 89 44 3d 00 66 43 c7 44 3d 09 f3 f3 <43> c6 44 3d 0b f3 0f 1f 44 00 00 65 44 8b 35 35 2f 9f 7e 48 c7 c0
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000802
RAX: f2f2f200f1f1f1f1 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8cb2aaa0
RBP: ffffc90000007bf0 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff215c249 R11: 1ffffffff215c248 R12: ffff888054e91868
R13: 1ffff92000000f68 R14: ffffc90000007c80 R15: dffffc0000000000
FS:  00007fde18a0c6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000054e02000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 __lock_task_sighand+0x42/0x2d0 kernel/signal.c:1394
 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:1752 [inline]
 __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1816
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878
 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 92 41 f7 48 89 df e8 96 57 42 f7 e8 a1 59 65 f7 fb bf 01 00 00 00 <e8> a6 d4 35 f7 65 8b 05 77 95 e0 75 85 c0 74 02 5b c3 e8 c4 a6 de
RSP: 0018:ffffc9000901fbb8 EFLAGS: 00000286
RAX: c5fdbc80fa2fe900 RBX: ffff888056ddef00 RCX: c5fdbc80fa2fe900
RDX: dffffc0000000000 RSI: ffffffff8a8bffe0 RDI: 0000000000000001
RBP: ffff888056ddf398 R08: dffffc0000000000 R09: ffffed100adbbde1
R10: ffffed100adbbde1 R11: 1ffff1100adbbde0 R12: 1ffff1100adbbe73
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+0xb0/0x1230 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 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: 0033:0x7fde17b8e927
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:00007fde18a0c0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fde17db5fa8 RCX: 00007fde17b8e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fde17db5fa8
RBP: 00007fde17db5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde17db5fac
R13: 0000000000000000 R14: 00007ffe71fcd380 R15: 00007ffe71fcd468
 </TASK>
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.142-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 a7 99 b0 f7 e9 4c ff ff ff e8 5d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 77 e5 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:ffffc90000177de8 EFLAGS: 000002c6
RAX: 969c7e16b2d6de00 RBX: ffffffff8a21be17 RCX: 969c7e16b2d6de00
RDX: 0000000000000001 RSI: ffffffff8a8bffe0 RDI: ffffffff8adf1720
RBP: ffffc90000177f20 R08: dffffc0000000000 R09: ffffed10171e6af6
R10: ffffed10171e6af6 R11: 1ffff110171e6af5 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff888017731dc0 R15: 1ffffffff1c3ec06
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000026f030 CR3: 000000007cde9000 CR4: 00000000003506e0
DR0: ffffffffffffffff DR1: 0000000000000047 DR2: 0000000000000005
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
 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>