rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=ce9c/0/0x1 softirq=89329/89338 fqs=1
	(t=10500 jiffies g=132973 q=90 ncpus=2)
rcu: rcu_preempt kthread starved for 10498 jiffies! g132973 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:27432 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 17947 Comm: syz.4.4511 Not tainted 6.1.139-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:__lock_release kernel/locking/lockdep.c:5367 [inline]
RIP: 0010:lock_release+0x2e1/0x910 kernel/locking/lockdep.c:5682
Code: 0f 85 86 02 00 00 48 8b 44 24 40 42 0f b6 04 28 84 c0 0f 85 74 04 00 00 48 8b 04 24 89 10 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <4c> 8b 74 24 08 74 0e 4c 89 e7 48 89 d3 e8 5d dc 6e 00 48 89 da 49
RSP: 0018:ffffc900001e0ae0 EFLAGS: 00000046
RAX: 1ffff1100f0b1c8e RBX: 1ffff1100f0b1c92 RCX: 0000000000000001
RDX: 0000000000000002 RSI: ffffffff8c92ab20 RDI: ffff88807858e470
RBP: ffffc900001e0bf8 R08: dffffc0000000000 R09: fffffbfff1bfcfb6
R10: fffffbfff1bfcfb6 R11: 1ffffffff1bfcfb5 R12: ffff88807858e470
R13: dffffc0000000000 R14: ffff88807858e490 R15: 1ffff9200003c168
FS:  00007fb088a596c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 000000001fb70000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:355 [inline]
 rcu_read_unlock include/linux/rcupdate.h:824 [inline]
 __lock_task_sighand+0x2b0/0x2d0 kernel/signal.c:1416
 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 ee 3e 4a f7 48 89 df e8 46 04 4b f7 e8 b1 06 6e f7 fb bf 01 00 00 00 <e8> 56 81 3e f7 65 8b 05 f7 42 e9 75 85 c0 74 02 5b c3 e8 44 54 e7
RSP: 0018:ffffc9000e317bb8 EFLAGS: 00000286
RAX: 4de94665c20f3100 RBX: ffff8880550ba500 RCX: 4de94665c20f3100
RDX: dffffc0000000000 RSI: ffffffff8a6c0000 RDI: 0000000000000001
RBP: ffff8880550ba798 R08: dffffc0000000000 R09: ffffed100aa174a1
R10: ffffed100aa174a1 R11: 1ffff1100aa174a0 R12: 1ffff1100aa174f3
R13: 0000000000000011 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: 0033:0x7fb087b8e969
Code: 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 01 48
RSP: 002b:00007fb088a59038 EFLAGS: 00000246
RAX: 0000000000fff700 RBX: 00007fb087db6160 RCX: 00007fb087b8e969
RDX: 00000000fffffef0 RSI: 00002000000008c0 RDI: 0000000000000006
RBP: 00007fb087c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb087db6160 R15: 00007ffc1e5e70f8
 </TASK>
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.139-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:736
Code: 48 89 df e8 67 3e b9 f7 e9 4c ff ff ff e8 4d 14 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d f7 92 4d 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:ffffffff8c607d88 EFLAGS: 000002c6
RAX: 45faae69ce500f00 RBX: ffffffff8a191097 RCX: 45faae69ce500f00
RDX: 0000000000000001 RSI: ffffffff8a6c0000 RDI: ffffffff8abf1020
RBP: ffffffff8c607ec0 R08: dffffc0000000000 R09: ffffed10171c6aee
R10: ffffed10171c6aee R11: 1ffff110171c6aed R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8c6bc680 R15: 1ffffffff1bfcff6
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556da4cb5000 CR3: 000000001fb70000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 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:733
 arch_call_rest_init+0xa/0xa init/main.c:893
 start_kernel+0x490/0x539 init/main.c:1140
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>