rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=37e/1/0x4000000000000000 softirq=30473/30476 fqs=16 (t=10502 jiffies g=45113 q=785) rcu: rcu_preempt kthread starved for 10006 jiffies! g45113 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:29512 pid: 13 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 schedule_timeout+0x148/0x250 kernel/time/timer.c:1878 rcu_gp_fqs_loop kernel/rcu/tree.c:1940 [inline] rcu_gp_kthread+0xbbe/0x1d70 kernel/rcu/tree.c:2113 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 NMI backtrace for cpu 0 CPU: 0 PID: 16736 Comm: syz-executor.1 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 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:337 print_cpu_stall kernel/rcu/tree_stall.h:569 [inline] check_cpu_stall kernel/rcu/tree_stall.h:643 [inline] rcu_pending kernel/rcu/tree.c:3751 [inline] rcu_sched_clock_irq.cold+0x472/0xec3 kernel/rcu/tree.c:2580 update_process_times+0x16d/0x200 kernel/time/timer.c:1782 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369 __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:1085 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102 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:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 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 ea 5b 6a f8 48 89 ef e8 72 10 6b f8 f6 c7 02 75 1a 53 9d 01 00 00 00 e8 61 20 5f f8 65 8b 05 8a c5 13 77 85 c0 74 0a 5b RSP: 0018:ffffc90000007e10 EFLAGS: 00000286 RAX: 000000000111c514 RBX: 0000000000000286 RCX: 1ffffffff19de351 RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000000 RBP: ffff8880b9e26a00 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817845a8 R11: 0000000000000000 R12: ffff8880b9e26a00 R13: ffff8880b9e26c80 R14: ffffffff85112250 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+0x2a5/0x9f7 kernel/softirq.c:343 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:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0010:queue_work_on+0x83/0xd0 kernel/workqueue.c:1530 Code: 31 ff 89 ee e8 be dd 28 00 40 84 ed 74 46 e8 34 d7 28 00 31 ff 48 89 de e8 1a df 28 00 48 85 db 75 26 e8 20 d7 28 00 41 56 9d <48> 83 c4 08 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 06 d7 28 RSP: 0018:ffffc9000900f530 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: ffff88806d010000 RSI: ffffffff81499e80 RDI: 0000000000000000 RBP: ffffc900098a8000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817845a8 R11: 0000000000000000 R12: ffff8880b9e31568 R13: ffff888010062c00 R14: 0000000000000293 R15: 0000000000000001 queue_work include/linux/workqueue.h:507 [inline] schedule_work include/linux/workqueue.h:568 [inline] __vfree_deferred mm/vmalloc.c:2307 [inline] vfree_atomic+0xac/0xe0 mm/vmalloc.c:2325 free_thread_stack kernel/fork.c:291 [inline] release_task_stack kernel/fork.c:428 [inline] put_task_stack+0x29c/0x480 kernel/fork.c:439 finish_task_switch.isra.0+0x557/0x7e0 kernel/sched/core.c:4222 context_switch kernel/sched/core.c:4316 [inline] __schedule+0x914/0x21a0 kernel/sched/core.c:5064 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:5224 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:40 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:394 [inline] zap_pte_range mm/memory.c:1320 [inline] zap_pmd_range mm/memory.c:1368 [inline] zap_pud_range mm/memory.c:1397 [inline] zap_p4d_range mm/memory.c:1418 [inline] unmap_page_range+0xf98/0x2640 mm/memory.c:1439 unmap_single_vma+0x198/0x300 mm/memory.c:1484 unmap_vmas+0x168/0x2e0 mm/memory.c:1516 exit_mmap+0x2b1/0x5a0 mm/mmap.c:3220 __mmput+0x122/0x470 kernel/fork.c:1083 mmput+0x53/0x60 kernel/fork.c:1104 exit_mm kernel/exit.c:501 [inline] do_exit+0xb6a/0x2ae0 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x3ec/0x2010 kernel/signal.c:2770 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: Unable to access opcode bytes at RIP 0x45e1ef. RSP: 002b:00007fb11b7bec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000045e219 RDX: 0000000000042000 RSI: 0000000000000004 RDI: 0000000000000007 RBP: 000000000119c068 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffdc6c5f68f R14: 00007fb11b7bf9c0 R15: 000000000119c034