rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=92a/1/0x4000000000000002 softirq=14461/14461 fqs=0 (t=10501 jiffies g=7125 q=72) rcu: rcu_preempt kthread starved for 10502 jiffies! g7125 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 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: 8704 Comm: blkid Not tainted 5.5.0-rc5-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:1517 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641 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:free_thread_stack+0x133/0x590 kernel/fork.c:280 Code: 00 ea ff ff 48 01 c7 be 03 00 00 00 e8 86 91 61 00 e9 5d 04 00 00 e8 3c 2c 2e 00 48 89 df 31 f6 e8 02 8d 6f 00 43 80 3c 2e 00 <74> 08 4c 89 e7 e8 73 94 6a 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48 RSP: 0018:ffffc90002857b28 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffea00025e6880 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea00025e6880 RBP: ffffc90002857b60 R08: 000000000003a728 R09: ffffed1013328ea1 R10: ffffed1013328ea1 R11: 0000000000000000 R12: ffff8880a404d6a0 R13: dffffc0000000000 R14: 1ffff11014809ad4 R15: ffff8880999474f8 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_read_unlock include/linux/rwlock_api_smp.h:227 [inline] _raw_read_unlock+0x3a/0x40 kernel/locking/spinlock.c:255 search_binary_handler+0x601/0x660 fs/exec.c:1670 exec_binprm fs/exec.c:1701 [inline] __do_execve_file+0x1573/0x1cd0 fs/exec.c:1821 do_execveat_common fs/exec.c:1867 [inline] do_execve fs/exec.c:1884 [inline] __do_sys_execve fs/exec.c:1960 [inline] __se_sys_execve fs/exec.c:1955 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:1955 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fc5b2847af0 Code: Bad RIP value. RSP: 002b:00007ffca81910e0 EFLAGS: 00000200 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000