rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=4645, q=22 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294966593-4294956091), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g4645 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:26560 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1674 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1873 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 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: 3589 Comm: syz-executor339 Not tainted 6.1.74-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4748 [inline] RIP: 0010:__lock_acquire+0x7e9/0x1f80 kernel/locking/lockdep.c:4999 Code: 50 0f b6 04 10 84 c0 0f 85 39 01 00 00 83 3d bd 3e 5e 10 00 74 67 31 db 48 81 c3 b8 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 <84> c0 0f 85 c4 00 00 00 8b 03 41 38 c7 41 0f b6 cf 41 89 c7 44 0f RSP: 0018:ffffc90000007a00 EFLAGS: 00000806 RAX: 0000000000000000 RBX: ffffffff9018b798 RCX: ffffffff816a525c RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff90491228 RBP: ffff888018eac680 R08: dffffc0000000000 R09: fffffbfff2092246 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffff888018eac680 R14: 0000000000000000 R15: 1ffff110031d5802 FS: 0000555555faa3c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbdb047c4c0 CR3: 000000007778e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x61/0x420 lib/debugobjects.c:772 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:481 __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 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: 61 b7 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 6e a9 d5 f6 48 89 df e8 d6 e6 d6 f6 e8 21 71 fc f6 fb bf 01 00 00 00 b6 75 c9 f6 65 8b 05 47 ae 6d 75 85 c0 74 02 5b c3 e8 84 cc 6b RSP: 0018:ffffc90003cafb30 EFLAGS: 00000286 RAX: e60f7d4372429500 RBX: ffff888027a44a00 RCX: ffffffff91c89103 RDX: dffffc0000000000 RSI: ffffffff8aebe640 RDI: 0000000000000001 RBP: ffffc90003cafc70 R08: dffffc0000000000 R09: ffffed1004f48941 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11004f489d3 R13: 000000001c000004 R14: 0000000000000021 R15: ffff888027a44e98 spin_unlock_irq include/linux/spinlock.h:400 [inline] get_signal+0x154b/0x17d0 kernel/signal.c:2865 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fbdb0464e79 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:00007fffafa15358 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fbdb0464e79 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000555555faa370 R13: 0000000000000003 R14: 00007fffafa153d0 R15: 00007fffafa153c0 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.491 msecs