rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=b92/1/0x4000000000000000 softirq=182934/182935 fqs=6 (t=10501 jiffies g=359501 q=738) rcu: rcu_preempt kthread starved for 10490 jiffies! g359501 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: rcu_preempt R running task 28472 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 0 CPU: 0 PID: 15058 Comm: syz-executor.4 Not tainted 5.8.0-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 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:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] RIP: 0010:_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 Code: 55 48 89 fd bf 01 00 00 00 e8 a2 d7 5b f9 45 31 c9 41 b8 01 00 00 00 31 c9 ff 74 24 08 48 8d 7d 18 31 d2 31 f6 e8 b6 79 66 f9 <48> 89 ef 58 5d e9 3c 66 67 f9 66 90 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0000:ffffc90000007cd8 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffff88800da9d010 RCX: ffffffff815a221b RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000286 RBP: ffff88800da9d0b0 R08: 0000000000000000 R09: ffffffff8c5eeaef R10: fffffbfff18bdd5d R11: 0000000000000001 R12: ffff88800da9d000 R13: ffff88800da9d0b0 R14: 1ffff92000000fa7 R15: ffff8880ae6255c0 spin_lock include/linux/spinlock.h:354 [inline] mrp_join_timer+0x23/0xc0 net/802/mrp.c:590 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/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+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:check_kcov_mode kernel/kcov.c:165 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x60 kernel/kcov.c:197 Code: 65 48 8b 14 25 c0 fe 01 00 65 8b 05 e0 b4 8d 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 35 8b 82 0c 14 00 00 85 c0 74 2b <8b> 82 e8 13 00 00 83 f8 02 75 20 48 8b 8a f0 13 00 00 8b 92 ec 13 RSP: 0000:ffffc9001be57770 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 8000000000000867 RCX: ffffffff81a40a80 RDX: ffff8881e90882c0 RSI: ffffffff81a40a8d RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: ffff8881e90882c7 R10: 0000000000000000 R11: 0000000000000000 R12: 80000001f87bf867 R13: 0000000000000867 R14: dffffc0000000000 R15: 0000000000749000 zap_pte_range mm/memory.c:1062 [inline] zap_pmd_range mm/memory.c:1193 [inline] zap_pud_range mm/memory.c:1222 [inline] zap_p4d_range mm/memory.c:1243 [inline] unmap_page_range+0xb7d/0x2b20 mm/memory.c:1264 unmap_single_vma+0x198/0x300 mm/memory.c:1309 unmap_vmas+0x168/0x2e0 mm/memory.c:1341 exit_mmap+0x2b1/0x530 mm/mmap.c:3183 __mmput+0x122/0x470 kernel/fork.c:1076 mmput+0x53/0x60 kernel/fork.c:1097 exit_mm kernel/exit.c:483 [inline] do_exit+0xa8b/0x29f0 kernel/exit.c:793 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x40b/0x1ee0 kernel/signal.c:2743 arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:135 [inline] exit_to_user_mode_prepare+0x172/0x1d0 kernel/entry/common.c:166 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:254 exc_page_fault+0xc2/0x160 arch/x86/mm/fault.c:1420 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538 RIP: 0033:0x403667 Code: Bad RIP value. RSP: 002b:000000000169fb10 EFLAGS: 00010287 RAX: 0000001b30221000 RBX: 000000006b42ba91 RCX: 0000001b31220000 RDX: 0000001b30221004 RSI: 000000000000111f RDI: ffffffffe8dc311e RBP: 0000000000000059 R08: 00000000e8dc311e R09: 00000000e8dc3122 R10: 000000000169fcd0 R11: 0000000000000246 R12: 000000000118cfc8 R13: 0000000080000000 R14: 00007fb767edc008 R15: 000000000000006a