rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=b0a/1/0x4000000000000002 softirq=11476/11476 fqs=1 
	(t=10501 jiffies g=6441 q=38)
rcu: rcu_preempt kthread starved for 10500 jiffies! g6441 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: 8310 Comm: blkid 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: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
 </IRQ>
RIP: 0010:__memcg_kmem_uncharge+0x0/0x1a0 mm/memcontrol.c:2909
Code: 00 eb 1b 83 3d 20 f1 8c 07 00 74 12 48 81 c3 08 02 00 00 48 89 df 4c 89 f6 e8 7c 87 ff ff 5b 41 5e 5d c3 0f 1f 80 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 50 89 f3 49 89 fc 48 b8 00
RSP: 0018:ffffc90001fa7ac0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81486ea4 RBX: ffffea0002326c00 RCX: ffff888094d3c5c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002326c00
RBP: ffffc90001fa7b00 R08: 000000000003a728 R09: ffffed10131bdb07
R10: ffffed10131bdb07 R11: 0000000000000000 R12: ffff888092a5e620
R13: dffffc0000000000 R14: 1ffff1101254bcc4 R15: ffff888098ded828
 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:compound_head include/linux/page-flags.h:176 [inline]
RIP: 0010:virt_to_head_page include/linux/mm.h:733 [inline]
RIP: 0010:virt_to_cache mm/slab.h:472 [inline]
RIP: 0010:cache_from_obj+0x3d/0x140 mm/slab.h:520
Code: 01 75 08 4c 89 f3 e9 d9 00 00 00 48 89 f7 e8 fa 68 85 ff 48 c1 e8 06 48 83 e0 c0 48 ba 00 00 00 00 00 ea ff ff 48 8b 4c 10 08 <f6> c1 01 0f 85 b9 00 00 00 48 01 d0 48 8b 48 08 48 89 c2 f6 c1 01
RSP: 0018:ffffc90001fa7d18 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 000000000268cf80 RBX: 0000000000000000 RCX: ffffea000268c648
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001fa7d28 R08: ffffffff813705e0 R09: fffffbfff1287a8d
R10: fffffbfff1287a8d R11: 0000000000000000 R12: ffff888094d3cd60
R13: ffff888094d3ccc0 R14: ffff8880aa9ec700 R15: ffff88809a33e600
 kmem_cache_free+0x13/0xf0 mm/slab.c:3686
 free_fs_struct fs/fs_struct.c:92 [inline]
 exit_fs+0x123/0x150 fs/fs_struct.c:108
 do_exit+0x57a/0x2020 kernel/exit.c:793
 do_group_exit+0x15c/0x2b0 kernel/exit.c:895
 __do_sys_exit_group+0x17/0x20 kernel/exit.c:906
 __se_sys_exit_group+0x14/0x20 kernel/exit.c:904
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:904
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fac912681e8
Code: Bad RIP value.
RSP: 002b:00007ffe29519758 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fac912681e8
RDX: 0000000000000002 RSI: 000000000000003c RDI: 0000000000000002
RBP: 00007fac9153d840 R08: 00000000000000e7 R09: ffffffffffffffa8
R10: 00007fac91543740 R11: 0000000000000246 R12: 00007fac9153d840
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000