rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=6613, q=12 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294969085-4294958583), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g6613 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:24016 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 5128 Comm: syz-executor577 Not tainted 6.9.0-rc6-syzkaller-00046-g18daea77cca6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:signal_wake_up include/linux/sched/signal.h:448 [inline] RIP: 0010:complete_signal+0x93f/0xcf0 kernel/signal.c:1065 Code: df 41 80 3c 04 00 74 08 4c 89 f7 e8 2b 92 9a 00 49 89 1e 41 bf 08 01 00 00 eb 0f e8 3b 41 39 00 45 31 ff eb 05 e8 31 41 39 00 <4c> 89 ef 44 89 fe e8 f6 74 ff ff 49 bf 00 00 00 00 00 fc ff df 4c RSP: 0018:ffffc90000007b20 EFLAGS: 00000046 RAX: ffffffff815ccff5 RBX: 0000000000000021 RCX: ffff88807e33bc00 RDX: 0000000080010003 RSI: 0000000000000021 RDI: 0000000000000009 RBP: ffffc90000007c10 R08: ffffffff815ccf7c R09: ffffffff815cc374 R10: 0000000000000002 R11: ffff88807e33bc00 R12: ffff88807e33bc00 R13: ffff88807e33bc00 R14: 0000000000000000 R15: 0000000000000000 FS: 000055556f7623c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 000000007e326000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: send_sigqueue+0x54c/0x760 kernel/signal.c:2022 posix_timer_event kernel/time/posix-timers.c:298 [inline] posix_timer_fn+0x18a/0x3a0 kernel/time/posix-timers.c:324 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x5a5/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 6a 5c f0 f5 48 89 df e8 82 9c f1 f5 e8 dd f6 1a f6 fb bf 01 00 00 00 72 61 e3 f5 65 8b 05 23 7c 81 74 85 c0 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc900037ffc70 EFLAGS: 00000282 RAX: ed9e159c55f54200 RBX: ffff88801978ae40 RCX: ffffffff946f6603 RDX: dffffc0000000000 RSI: ffffffff8bcab8a0 RDI: 0000000000000001 RBP: ffffc900037ffdb0 R08: ffffffff8fa7ccef R09: 1ffffffff1f4f99d R10: dffffc0000000000 R11: fffffbfff1f4f99e R12: 0000000000000021 R13: 1ffff110032f165b R14: ffff88801978b2d8 R15: ffff88801978ae40 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x14dd/0x1740 kernel/signal.c:2914 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f48da4b8e79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 18 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:00007ffe06b03b28 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f48da4b8e79 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000055556f762370 R13: 0000000000000000 R14: 00007ffe06b03ba0 R15: 00007ffe06b03b90 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.710 msecs