rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=ef2/1/0x4000000000000002 softirq=11122/11122 fqs=8 (t=10501 jiffies g=6441 q=329) rcu: rcu_preempt kthread starved for 10486 jiffies! g6441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29104 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 7901 Comm: udevd Not tainted 5.4.0-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+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:mod_memcg_page_state+0x123/0x190 include/linux/memcontrol.h:653 Code: e8 f2 9e 69 00 48 83 3d 12 22 c2 07 00 74 70 e8 e3 27 2e 00 4c 89 ff 57 9d 0f 1f 44 00 00 e8 f4 c2 33 00 eb 43 e8 cd 27 2e 00 3c e8 86 c0 33 00 48 c7 c0 28 96 0a 89 48 c1 e8 03 42 80 3c 20 RSP: 0018:ffffc90006f87898 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff8880940b45c0 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea000261ee80 RBP: ffffc90006f878b8 R08: 000000000003a768 R09: ffffed10151b0ab7 R10: ffffed10151b0ab7 R11: 0000000000000000 R12: dffffc0000000000 R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a8d855a8 free_thread_stack+0x168/0x590 kernel/fork.c:280 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xcc/0xe0 kernel/locking/spinlock.c:191 debug_object_activate+0x2f7/0x6f0 lib/debugobjects.c:660 debug_object_activate+0x185/0x6f0 lib/debugobjects.c:678 debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline] __call_rcu+0x3d/0x670 kernel/rcu/tree.c:2595 call_rcu+0xb/0x10 kernel/rcu/tree.c:2682 destroy_inode fs/inode.c:285 [inline] evict+0x64b/0x6c0 fs/inode.c:591 iput_final fs/inode.c:1563 [inline] iput+0x508/0x690 fs/inode.c:1589 dentry_unlink_inode+0x2e0/0x3d0 fs/dcache.c:374 __dentry_kill+0x3e2/0x5e0 fs/dcache.c:579 dentry_kill fs/dcache.c:673 [inline] dput+0x460/0x6f0 fs/dcache.c:859 do_renameat2+0x69b/0xff0 fs/namei.c:4627 __do_sys_rename fs/namei.c:4669 [inline] __se_sys_rename fs/namei.c:4667 [inline] __x64_sys_rename+0x68/0x80 fs/namei.c:4667 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff3c1304527 Code: 32 00 64 83 38 15 74 07 b8 ff ff ff ff 5b c3 48 89 df e8 1c c1 07 00 85 c0 75 ed 31 c0 eb d3 90 90 90 90 b8 52 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 f8 32 00 31 d2 48 29 c2 64 RSP: 002b:00007ffc18adc7b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff3c1304527 RDX: 00007ff3c1635e98 RSI: 00007ffc18adc7f0 RDI: 00007ffc18adcbf0 RBP: 0000000000d97520 R08: 00007ff3c1c777a0 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000d902d0 R13: 0000000000d7e250 R14: 00007ffc18adc7f0 R15: 0000000000000001