rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=7841, q=540 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294956928-4294946425), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g7841 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     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: 4319 Comm: syz-executor191 Not tainted 6.1.138-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:820 [inline]
RIP: 0010:__lock_task_sighand+0x232/0x2d0 kernel/signal.c:1416
Code: 00 48 c7 c2 80 1f 6b 8a e8 9b 45 13 00 e9 15 ff ff ff e8 f1 83 30 00 49 89 ed e8 29 f7 be 08 89 c5 31 ff 89 c6 e8 3e 87 30 00 <85> ed 74 10 e8 85 b2 1a 00 84 c0 74 0e e8 cc 83 30 00 eb 56 e8 c5
RSP: 0018:ffffc90000007c08 EFLAGS: 00000006
RAX: ffffffff81504fd2 RBX: ffff88802a8726d8 RCX: 0000000000010000
RDX: ffff88802a871dc0 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000000f5c R11: 1ffff92000000f5c R12: ffff8880240d2500
R13: ffffffff81504dc5 R14: ffff8880240d2500 R15: 1ffff1100550e4db
FS:  0000555585bd9480(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000007e406000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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:359 [inline]
 posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:385
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x522/0xc80 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1817
 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 4e 1b 4a f7 48 89 df e8 a6 e0 4a f7 e8 11 e3 6d f7 fb bf 01 00 00 00 <e8> b6 5d 3e f7 65 8b 05 b7 22 e9 75 85 c0 74 02 5b c3 e8 04 34 e7
RSP: 0018:ffffc90004057bb8 EFLAGS: 00000286
RAX: ddde44c84295e600 RBX: ffff8880240d2500 RCX: ddde44c84295e600
RDX: dffffc0000000000 RSI: ffffffff8a6bfe00 RDI: 0000000000000001
RBP: ffff8880240d2998 R08: dffffc0000000000 R09: ffffed100481a4a1
R10: ffffed100481a4a1 R11: 1ffff1100481a4a0 R12: 1ffff1100481a533
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: 0033:0x7f7dad8cdae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 1f 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff719f60a8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f7dad8cdae9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7dad91e504
R13: 00007fff719f6400 R14: 00007fff719f60f0 R15: 0000000000000000
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.001 msecs