rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=226/1/0x4000000000000000 softirq=150462/150463 fqs=6 (t=10500 jiffies g=248413 q=93) rcu: rcu_preempt kthread starved for 10488 jiffies! g248413 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: rcu_preempt I29120 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3455 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4180 schedule+0xd0/0x2a0 kernel/sched/core.c:4255 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897 rcu_gp_fqs_loop kernel/rcu/tree.c:1870 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2040 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 1 CPU: 1 PID: 26841 Comm: syz-executor.3 Not tainted 5.8.0-rc2-next-20200626-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:165 [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:3624 [inline] rcu_sched_clock_irq.cold+0x5b3/0xcbd kernel/rcu/tree.c:2508 update_process_times+0x25/0x60 kernel/time/timer.c:1726 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x108/0x290 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 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+0x4f/0x120 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline] RIP: 0010:lock_acquire+0x270/0xad0 kernel/locking/lockdep.c:4962 Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 f8 06 00 00 48 83 3d ad bf 5a 08 00 0f 84 a6 05 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 10 48 c7 RSP: 0018:ffffc90000da8bf0 EFLAGS: 00000282 RAX: 1ffffffff1369fe0 RBX: ffff88806064a140 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8c59cae7 R10: fffffbfff18b395c R11: 0000000000000000 R12: 0000000000000000 R13: ffff88800ff23478 R14: 0000000000000000 R15: ffff88806064a140 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] garp_join_timer+0x20/0xf0 net/802/garp.c:405 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers.part.0+0x54c/0xa20 kernel/time/timer.c:1773 __run_timers kernel/time/timer.c:1745 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1786 __do_softirq+0x34c/0xa60 kernel/softirq.c:292 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+0x111/0x170 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:387 [inline] __irq_exit_rcu kernel/softirq.c:417 [inline] irq_exit_rcu+0x229/0x270 kernel/softirq.c:429 sysvec_apic_timer_interrupt+0x54/0x120 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:__sanitizer_cov_trace_pc+0x49/0x60 kernel/kcov.c:203 Code: 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 00 00 48 8b 01 48 83 c0 01 <48> 39 c2 76 07 48 89 34 c1 48 89 01 c3 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ffffc90005347838 EFLAGS: 00000206 RAX: 000000000000b36c RBX: 8000000059ae3005 RCX: ffffc9000fb4c000 RDX: 0000000000040000 RSI: ffffffff81e3de4c RDI: ffff8880a2e26980 RBP: 00007f36d8692000 R08: 0000000000000001 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000000 R12: 8000000059ae3007 R13: 0000000000000004 R14: ffff888207228490 R15: 00007f36d8800000 clear_refs_pte_range+0x7bc/0xe80 fs/proc/task_mmu.c:1056 walk_pmd_range mm/pagewalk.c:89 [inline] walk_pud_range mm/pagewalk.c:160 [inline] walk_p4d_range mm/pagewalk.c:193 [inline] walk_pgd_range mm/pagewalk.c:229 [inline] __walk_page_range+0xeed/0x22c0 mm/pagewalk.c:331 walk_page_range+0x20d/0x400 mm/pagewalk.c:427 clear_refs_write+0x785/0x920 fs/proc/task_mmu.c:1201 do_loop_readv_writev fs/read_write.c:718 [inline] do_loop_readv_writev fs/read_write.c:702 [inline] do_iter_write+0x48b/0x5f0 fs/read_write.c:1001 vfs_writev+0x1aa/0x2e0 fs/read_write.c:1072 do_writev+0x139/0x300 fs/read_write.c:1115 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb19 Code: Bad RIP value. RSP: 002b:00007f36d7e10c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000050ee40 RCX: 000000000045cb19 RDX: 0000000000000001 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d61 R14: 00000000004cb818 R15: 00007f36d7e116d4