rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=eea/1/0x4000000000000000 softirq=50659/50664 fqs=9 (t=10500 jiffies g=77489 q=1301) rcu: rcu_preempt kthread starved for 5494 jiffies! g77489 f0x0 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:28880 pid: 11 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3779 [inline] __schedule+0x893/0x2130 kernel/sched/core.c:4528 schedule+0xcf/0x270 kernel/sched/core.c:4606 schedule_timeout+0x148/0x250 kernel/time/timer.c:1871 rcu_gp_fqs_loop kernel/rcu/tree.c:1925 [inline] rcu_gp_kthread+0xb4c/0x1c90 kernel/rcu/tree.c:2099 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 NMI backtrace for cpu 1 CPU: 1 PID: 25114 Comm: syz-executor.0 Not tainted 5.10.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x1e3/0x21e kernel/rcu/tree_stall.h:331 print_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:637 [inline] rcu_pending kernel/rcu/tree.c:3694 [inline] rcu_sched_clock_irq.cold+0x472/0xee8 kernel/rcu/tree.c:2567 update_process_times+0x77/0xd0 kernel/time/timer.c:1709 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x1ce/0xea0 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1097 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline] sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x25/0x50 kernel/locking/spinlock.c:191 Code: f8 5d c3 66 90 55 48 89 fd 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 fa 28 6e f8 48 89 ef e8 82 dd 6e f8 f6 c7 02 75 1a 53 9d 01 00 00 00 e8 91 49 63 f8 65 8b 05 ba f3 19 77 85 c0 74 0a 5b RSP: 0018:ffffc90000d90e10 EFLAGS: 00000286 RAX: 000000000142f3fc RBX: 0000000000000286 RCX: ffffffff8155a917 RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000000 RBP: ffff8880b9f26900 R08: 0000000000000001 R09: ffffffff8ebaf677 R10: fffffbfff1d75ece R11: 0000000000000001 R12: ffff8880b9f26900 R13: ffff8880b9f26b80 R14: ffffffff850f33c0 R15: dffffc0000000000 __run_hrtimer kernel/time/hrtimer.c:1515 [inline] __hrtimer_run_queues+0x5c0/0xea0 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1600 __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x132/0x200 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:270 Code: 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 0c ff ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <48> 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 ea fe ff ff RSP: 0018:ffffc900023df790 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81a4a66c RDX: ffff88802e968000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffea0000c4c6c0 R08: 0000000000000000 R09: ffffea0000c4c6f3 R10: 00000000000000ca R11: 0000000000000000 R12: ffffea0000c4c6f0 R13: ffff88802e40b888 R14: dffffc0000000000 R15: 0000000000512000 zap_pte_range mm/memory.c:1256 [inline] zap_pmd_range mm/memory.c:1357 [inline] zap_pud_range mm/memory.c:1386 [inline] zap_p4d_range mm/memory.c:1407 [inline] unmap_page_range+0xeb2/0x2640 mm/memory.c:1428 unmap_single_vma+0x198/0x300 mm/memory.c:1473 unmap_vmas+0x168/0x2e0 mm/memory.c:1505 exit_mmap+0x2b1/0x530 mm/mmap.c:3220 __mmput+0x122/0x470 kernel/fork.c:1079 mmput+0x53/0x60 kernel/fork.c:1100 exit_mm kernel/exit.c:486 [inline] do_exit+0xa72/0x29b0 kernel/exit.c:796 do_group_exit+0x125/0x310 kernel/exit.c:906 get_signal+0x42a/0x1f10 kernel/signal.c:2758 arch_do_signal+0x82/0x2390 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0x100/0x1a0 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e159 Code: Unable to access opcode bytes at RIP 0x45e12f. RSP: 002b:00007f69a45d9c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000004 RBX: 0000000000000003 RCX: 000000000045e159 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffe83c685ef R14: 00007f69a45da9c0 R15: 000000000119bf8c