rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=e36/1/0x4000000000000002 softirq=11699/11699 fqs=4 
	(t=10500 jiffies g=5965 q=195)
rcu: rcu_preempt kthread starved for 10491 jiffies! g5965 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: 8179 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:
 <IRQ>
 __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
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x35/0x50 kernel/kcov.c:108
Code: 02 00 65 8b 15 b8 81 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 83 fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 <8b> 89 84 13 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a c3 0f 1f
RSP: 0018:ffffc90002217b70 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487326 RBX: ffffea00023a1e40 RCX: ffff8880951f6040
RDX: ffffc90002009000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc90002217b98 R08: 000000000003a768 R09: ffffed10153772af
R10: ffffed10153772af R11: 0000000000000000 R12: ffff888090b0da20
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a9bb9568
 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:slab_alloc mm/slab.c:3313 [inline]
RIP: 0010:kmem_cache_alloc+0x1a8/0x2e0 mm/slab.c:3484
Code: 8b 7d d0 57 9d 0f 1f 44 00 00 e8 83 b1 ca ff eb 1e e8 1c af ca ff 48 83 3d 7c 10 59 07 00 0f 84 33 01 00 00 48 8b 7d d0 57 9d <0f> 1f 44 00 00 41 0f 18 0e e9 21 00 00 00 89 d8 c1 e8 08 83 e0 01
RSP: 0018:ffffc90002217df0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: ffff8880951f68d4 RBX: 0000000000000cc0 RCX: 0000000000040000
RDX: ffffc90002009000 RSI: 0000000000000050 RDI: 0000000000000286
RBP: ffffc90002217e28 R08: ffff8880951f6898 R09: ffffed101553fbc1
R10: ffffed101553fbc1 R11: 0000000000000000 R12: ffff8880aa9f9a80
R13: ffff8880aa9f9a80 R14: ffff88809e62c700 R15: 0000000000000cc0
 getname_flags+0xba/0x640 fs/namei.c:138
 getname fs/namei.c:209 [inline]
 user_path_create fs/namei.c:3688 [inline]
 do_mkdirat+0x3c/0x320 fs/namei.c:3826
 __do_sys_mkdir fs/namei.c:3850 [inline]
 __se_sys_mkdir fs/namei.c:3848 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3848
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fdfc7305c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045a679
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdfc73066d4
R13: 00000000004c0064 R14: 00000000004de498 R15: 00000000ffffffff