rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10499 ticks this GP) idle=306/1/0x4000000000000002 softirq=9602/9604 fqs=2814 (t=10501 jiffies g=5649 q=98) rcu: rcu_preempt kthread starved for 4874 jiffies! g5649 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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 0 CPU: 0 PID: 8025 Comm: syz-executor.0 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:ffffc900020377f8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff88809636c180 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0001b1e780 RBP: ffffc90002037818 R08: dffffc0000000000 R09: fffffbfff120248a R10: fffffbfff120248a R11: 0000000000000000 R12: dffffc0000000000 R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880944378a8 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_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:lock_anon_vma_root mm/rmap.c:234 [inline] RIP: 0010:anon_vma_clone+0x239/0x600 mm/rmap.c:298 Code: 89 02 00 00 e8 28 9a cf ff 48 89 5d b0 48 83 c3 f8 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 0a 11 0b 00 48 8b 1b <48> 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 f1 10 0b 00 RSP: 0018:ffffc90002037a78 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff110150c1ad3 RBX: ffff8880a8303960 RCX: ffff88809636c180 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90002037ae8 R08: ffffffff81a701ca R09: ffffed1015da6fcd R10: ffffed1015da6fcd R11: 0000000000000000 R12: ffff88809e66ba80 R13: ffff88809e5b19d0 R14: ffff8880a0a5fe10 R15: dffffc0000000000 anon_vma_fork+0x91/0x540 mm/rmap.c:352 dup_mmap+0x6b8/0xe00 kernel/fork.c:559 dup_mm+0x9e/0x340 kernel/fork.c:1360 copy_mm kernel/fork.c:1416 [inline] copy_process+0x1e49/0x5510 kernel/fork.c:2072 _do_fork+0x13e/0x660 kernel/fork.c:2421 __do_sys_clone kernel/fork.c:2576 [inline] __se_sys_clone kernel/fork.c:2557 [inline] __x64_sys_clone+0x20b/0x250 kernel/fork.c:2557 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c4a Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00 RSP: 002b:00007ffea721aca0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffea721aca0 RCX: 0000000000458c4a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffea721ace0 R08: 0000000000000001 R09: 0000000001970940 R10: 0000000001970c10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffea721ad30