rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=d1a/1/0x4000000000000000 softirq=31234/31236 fqs=3 (t=10501 jiffies g=46917 q=360) rcu: rcu_preempt kthread starved for 10489 jiffies! g46917 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:28872 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2005 [inline] rcu_gp_kthread+0xd07/0x2250 kernel/rcu/tree.c:2178 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 18227 Comm: syz-executor.2 Not tainted 5.12.0-rc8-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+0x141/0x1d7 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_check_gp_kthread_starvation+0x1c7/0x1e4 kernel/rcu/tree_stall.h:478 print_cpu_stall kernel/rcu/tree_stall.h:620 [inline] check_cpu_stall kernel/rcu/tree_stall.h:697 [inline] rcu_pending kernel/rcu/tree.c:3830 [inline] rcu_sched_clock_irq.cold+0x4f2/0x11dd kernel/rcu/tree.c:2650 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 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:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 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+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 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 4a f9 53 f8 48 89 ef e8 82 af 54 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 63 7d 48 f8 65 8b 05 0c 48 fc 76 85 c0 74 0a 5b 5d c3 e8 d0 3c RSP: 0018:ffffc90000007e30 EFLAGS: 00000206 RAX: 0000000000000016 RBX: 0000000000000200 RCX: 1ffffffff1f5430a RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001 RBP: ffff8880b9c26340 R08: 0000000000000001 R09: ffffffff8fa9a8b7 R10: 0000000000000001 R11: 0000000000000000 R12: 0000005c77f22562 R13: ffff8880b9c265c0 R14: ffff8880b9c26340 R15: ffffffff851e37c0 __run_hrtimer kernel/time/hrtimer.c:1533 [inline] __hrtimer_run_queues+0x51a/0xe40 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu kernel/softirq.c:422 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 40 00 65 8b 05 69 fa 8d 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 f0 01 00 a9 RSP: 0018:ffffc900021ff798 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffea0000c14600 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888014593880 RDI: 0000000000000003 RBP: ffffea0000c14600 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81a70379 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880127811c8 R14: dffffc0000000000 R15: 000000000043a000 PageSwapBacked include/linux/page-flags.h:357 [inline] mm_counter_file include/linux/mm.h:1917 [inline] mm_counter include/linux/mm.h:1926 [inline] zap_pte_range mm/memory.c:1269 [inline] zap_pmd_range mm/memory.c:1374 [inline] zap_pud_range mm/memory.c:1403 [inline] zap_p4d_range mm/memory.c:1424 [inline] unmap_page_range+0xda7/0x2650 mm/memory.c:1445 unmap_single_vma+0x198/0x300 mm/memory.c:1490 unmap_vmas+0x16d/0x2f0 mm/memory.c:1522 exit_mmap+0x2a8/0x590 mm/mmap.c:3218 __mmput+0x122/0x470 kernel/fork.c:1090 mmput+0x58/0x60 kernel/fork.c:1111 exit_mm kernel/exit.c:501 [inline] do_exit+0xb0a/0x2a60 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2150 kernel/signal.c:2781 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789 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:208 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:314 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007ff31f469218 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 000000000056bf68 RCX: 00000000004665f9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000056bf6c RBP: 000000000056bf60 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c R13: 00007ffd970169cf R14: 00007ff31f469300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 18227 Comm: syz-executor.2 Not tainted 5.12.0-rc8-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+0x141/0x1d7 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+0x222/0x2a7 kernel/rcu/tree_stall.h:341 print_cpu_stall kernel/rcu/tree_stall.h:622 [inline] check_cpu_stall kernel/rcu/tree_stall.h:697 [inline] rcu_pending kernel/rcu/tree.c:3830 [inline] rcu_sched_clock_irq.cold+0x4f7/0x11dd kernel/rcu/tree.c:2650 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 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:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 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+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 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 4a f9 53 f8 48 89 ef e8 82 af 54 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 63 7d 48 f8 65 8b 05 0c 48 fc 76 85 c0 74 0a 5b 5d c3 e8 d0 3c RSP: 0018:ffffc90000007e30 EFLAGS: 00000206 RAX: 0000000000000016 RBX: 0000000000000200 RCX: 1ffffffff1f5430a RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001 RBP: ffff8880b9c26340 R08: 0000000000000001 R09: ffffffff8fa9a8b7 R10: 0000000000000001 R11: 0000000000000000 R12: 0000005c77f22562 R13: ffff8880b9c265c0 R14: ffff8880b9c26340 R15: ffffffff851e37c0 __run_hrtimer kernel/time/hrtimer.c:1533 [inline] __hrtimer_run_queues+0x51a/0xe40 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu kernel/softirq.c:422 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 40 00 65 8b 05 69 fa 8d 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 f0 01 00 a9 RSP: 0018:ffffc900021ff798 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffea0000c14600 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888014593880 RDI: 0000000000000003 RBP: ffffea0000c14600 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81a70379 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880127811c8 R14: dffffc0000000000 R15: 000000000043a000 PageSwapBacked include/linux/page-flags.h:357 [inline] mm_counter_file include/linux/mm.h:1917 [inline] mm_counter include/linux/mm.h:1926 [inline] zap_pte_range mm/memory.c:1269 [inline] zap_pmd_range mm/memory.c:1374 [inline] zap_pud_range mm/memory.c:1403 [inline] zap_p4d_range mm/memory.c:1424 [inline] unmap_page_range+0xda7/0x2650 mm/memory.c:1445 unmap_single_vma+0x198/0x300 mm/memory.c:1490 unmap_vmas+0x16d/0x2f0 mm/memory.c:1522 exit_mmap+0x2a8/0x590 mm/mmap.c:3218 __mmput+0x122/0x470 kernel/fork.c:1090 mmput+0x58/0x60 kernel/fork.c:1111 exit_mm kernel/exit.c:501 [inline] do_exit+0xb0a/0x2a60 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2150 kernel/signal.c:2781 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789 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:208 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:314 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007ff31f469218 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 000000000056bf68 RCX: 00000000004665f9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000056bf6c RBP: 000000000056bf60 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c R13: 00007ffd970169cf R14: 00007ff31f469300 R15: 0000000000022000