rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=4c2/1/0x4000000000000002 softirq=11444/11445 fqs=31 (t=10500 jiffies g=6501 q=321) rcu: rcu_preempt kthread starved for 10429 jiffies! g6501 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: 8225 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:__memcg_kmem_uncharge+0x213/0x2e0 mm/memcontrol.c:2925 Code: a4 ff 48 c7 c7 98 4b 0d 89 e8 59 97 00 00 bf 01 00 00 00 e8 2f e3 9b ff 65 8b 05 d4 fd 4a 7e 85 c0 74 53 48 83 c4 08 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 49 8d 5f 10 48 89 df be 08 00 00 00 e8 04 RSP: 0018:ffffc90001e37620 EFLAGS: 00000292 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffea0002819680 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002819680 RBP: ffffc90001e37638 R08: dffffc0000000000 R09: fffffbfff120248a R10: fffffbfff120248a R11: 0000000000000000 R12: ffff8880a2fb40a0 R13: 1ffffd40005032d7 R14: ffffea00028196b8 R15: 0000000000000000 memcg_kmem_uncharge include/linux/memcontrol.h:1402 [inline] free_thread_stack+0x12e/0x590 kernel/fork.c:284 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_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:seqcount_lockdep_reader_access include/linux/seqlock.h:83 [inline] RIP: 0010:read_seqcount_begin+0x139/0x1b0 include/linux/seqlock.h:164 Code: 28 96 0a 89 48 c1 e8 03 42 80 3c 28 00 74 0c 48 c7 c7 28 96 0a 89 e8 46 f9 07 00 48 83 3d 66 7c 60 07 00 74 74 4c 89 ff 57 9d <0f> 1f 44 00 00 4c 89 f3 48 c1 eb 03 42 8a 04 2b 84 c0 74 43 44 89 RSP: 0000:ffffc90001e37890 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff12152c5 RBX: ffff88812fffb760 RCX: ffffffff815c0597 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffffc90001e378b8 R08: ffff88809ecaab58 R09: fffffbfff13c8d2d R10: fffffbfff13c8d2d R11: 0000000000000000 R12: ffffffff81aa16cb R13: dffffc0000000000 R14: ffff88812fffb758 R15: 0000000000000286 read_seqbegin include/linux/seqlock.h:433 [inline] zone_span_seqbegin include/linux/memory_hotplug.h:75 [inline] page_outside_zone_boundaries mm/page_alloc.c:569 [inline] bad_range+0x7b/0x240 mm/page_alloc.c:598 rmqueue+0xdd/0x2080 mm/page_alloc.c:3313 get_page_from_freelist+0x746/0xaa0 mm/page_alloc.c:3692 __alloc_pages_nodemask+0x264/0x5d0 mm/page_alloc.c:4756 alloc_pages_vma+0x4f7/0xd50 mm/mempolicy.c:2170 alloc_zeroed_user_highpage_movable include/linux/highmem.h:208 [inline] do_anonymous_page+0x327/0x1610 mm/memory.c:3098 handle_pte_fault mm/memory.c:3943 [inline] __handle_mm_fault mm/memory.c:4075 [inline] handle_mm_fault+0x1bce/0x2890 mm/memory.c:4112 do_user_addr_fault+0x589/0xaf0 arch/x86/mm/fault.c:1441 __do_page_fault+0xd3/0x1f0 arch/x86/mm/fault.c:1506 do_page_fault+0x99/0xb0 arch/x86/mm/fault.c:1530 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1203 RIP: 0033:0x7fd8cce9f2c9 Code: fd 4c 39 eb 4c 0f 46 eb 49 83 fd 14 77 5b 4d 85 ed 74 29 4b 8d 0c 2c 48 89 f8 0f 1f 80 00 00 00 00 41 0f b6 14 24 49 83 c4 01 <88> 10 48 83 c0 01 49 39 cc 75 ec 4c 01 ef 48 89 7d 28 4c 29 eb 48 RSP: 002b:00007ffec2b868e0 EFLAGS: 00010202 RAX: 00007fd8cd7fc000 RBX: 0000000000000002 RCX: 0000000000420726 RDX: 000000000000004e RSI: 0000000000420724 RDI: 00007fd8cd7fc000 RBP: 0000000000f07c30 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000022 R11: 00000000ffffffff R12: 0000000000420725 R13: 0000000000000002 R14: 0000000000000002 R15: 0000000000420724