rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 0, t=10502 jiffies, g=189545, q=100) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295056439-4295045937), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g189545 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=54360 rcu: rcu_preempt kthread starved for 10502 jiffies! g189545 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28864 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1878 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 8485 Comm: syz-executor.4 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:98 [inline] RIP: 0010:do_raw_spin_unlock+0x7d/0x230 kernel/locking/spinlock_debug.c:138 Code: 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 6b 01 00 00 8b 45 00 <85> c0 0f 84 f4 00 00 00 4c 8d 6d 10 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000dc0df8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000046 RCX: ffffffff815b7a10 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b9d423c0 RBP: ffff8880b9d423c0 R08: 0000000000000000 R09: ffff8880b9d423c3 R10: ffffed10173a8478 R11: 0000000000000000 R12: 17998690af330d21 R13: ffff8880b9d424c0 R14: ffff8880b9d423c0 R15: ffffffff874c26c0 FS: 0000000002bda400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000014a53ad CR3: 0000000078484000 CR4: 0000000000350ee0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irqrestore+0x1e/0x70 kernel/locking/spinlock.c:191 __run_hrtimer kernel/time/hrtimer.c:1533 [inline] __hrtimer_run_queues+0x51a/0xe50 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191 Code: 74 24 10 e8 3a 97 2e f8 48 89 ef e8 e2 0c 2f f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 c3 e6 22 f8 65 8b 05 bc 82 d5 76 85 c0 74 0a 5b 5d c3 e8 a0 3e RSP: 0018:ffffc90001b1fc38 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1ad8511 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff904a3908 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817babe8 R11: 0000000000000000 R12: ffffc90001b1fd98 R13: 1ffff92000363f99 R14: ffffffff904a3908 R15: ffffffff904a3900 __debug_object_init+0x409/0xd10 lib/debugobjects.c:600 hrtimer_init_sleeper_on_stack kernel/time/hrtimer.c:445 [inline] hrtimer_nanosleep+0x173/0x4a0 kernel/time/hrtimer.c:1947 common_nsleep+0xa2/0xc0 kernel/time/posix-timers.c:1227 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1267 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline] __x64_sys_clock_nanosleep+0x2f4/0x430 kernel/time/posix-timers.c:1245 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x48a7b1 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:00007ffe46ca1e70 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 000000000000135e RCX: 000000000048a7b1 RDX: 00007ffe46ca1eb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffe46ca1f4c R08: 0000000000000000 R09: 00007ffe46de6080 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 000000000010977f R14: 0000000000000000 R15: 00007ffe46ca1fb0