rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=942/1/0x4000000000000002 softirq=11374/11374 fqs=5 
	(t=10501 jiffies g=6525 q=86)
rcu: rcu_preempt kthread starved for 10492 jiffies! g6525 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: 8267 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+0x31/0x50 kernel/kcov.c:107
Code: 0c 25 c0 1d 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
RSP: 0018:ffffc90002577868 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81486ea4 RBX: ffffea00029b7980 RCX: ffff88808a416040
RDX: ffffc90001dc9000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc900025778a8 R08: dffffc0000000000 R09: fffffbfff120248a
R10: fffffbfff120248a R11: 0000000000000000 R12: ffff888094827320
R13: dffffc0000000000 R14: 1ffff11012904e64 R15: ffff8880a2b858a8
 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
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4214
 __mutex_lock_common+0x1411/0x2e10 kernel/locking/mutex.c:1036
 __mutex_lock kernel/locking/mutex.c:1106 [inline]
 mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1121
 __blkdev_get+0x1de/0x1310 fs/block_dev.c:1588
 blkdev_get+0xac/0x3f0 fs/block_dev.c:1736
 blkdev_get_by_path+0x19b/0x270 fs/block_dev.c:1795
 mount_bdev+0x51/0x390 fs/super.c:1373
 jfs_do_mount+0x34/0x40 fs/jfs/super.c:676
 legacy_get_tree+0xf9/0x1a0 fs/fs_context.c:647
 vfs_get_tree+0x8b/0x2a0 fs/super.c:1545
 do_new_mount fs/namespace.c:2822 [inline]
 do_mount+0x16bb/0x24f0 fs/namespace.c:3142
 ksys_mount+0xcc/0x100 fs/namespace.c:3351
 __do_sys_mount fs/namespace.c:3365 [inline]
 __se_sys_mount fs/namespace.c:3362 [inline]
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3362
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d0ca
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8c fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 2a 8c fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f209dd09a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f209dd09b40 RCX: 000000000045d0ca
RDX: 00007f209dd09ae0 RSI: 0000000020000400 RDI: 00007f209dd09b00
RBP: 0000000000000000 R08: 00007f209dd09b40 R09: 00007f209dd09ae0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000003
R13: 00000000004caa6e R14: 00000000004e3e98 R15: 00000000ffffffff