rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10499 ticks this GP) idle=0b9/1/0x4000000000000000 softirq=65823/65823 fqs=0
(t=10500 jiffies g=111905 q=133)
rcu: rcu_preempt kthread starved for 10500 jiffies! g111905 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:28952 pid: 14 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:4969 [inline]
__schedule+0xa9a/0x4940 kernel/sched/core.c:6250
schedule+0xd2/0x260 kernel/sched/core.c:6323
schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955
rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 32653 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:330 [inline]
RIP: 0010:rcu_is_watching+0x58/0xb0 kernel/rcu/tree.c:1121
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 51 48 03 1c ed a0 78 34 8b 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 19 8b 03 83 e0 01
RSP: 0018:ffffc90000fd8d70 EFLAGS: 00000806
RAX: dffffc0000000000 RBX: ffff8880b9d3aad0 RCX: ffffffff815c14c8
RDX: 0000000000000000 RSI: 0000000000010002 RDI: ffffffff8b3478a8
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8d6f8917
R10: fffffbfff1adf122 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: ffffffff8b9a0248 R15: 0000000000000000
FS: 00007f6e9d7c6700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e529000 CR3: 000000006b4be000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5611
seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline]
ktime_get+0x7c/0x470 kernel/time/timekeeping.c:827
clockevents_program_event+0x141/0x370 kernel/time/clockevents.c:326
tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44
hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
__sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:277 [inline]
RIP: 0010:path_init+0x1b0/0x1920 fs/namei.c:2335
Code: ef 41 83 e7 01 44 89 fe e8 8d 36 ab ff 45 85 ff 74 45 48 b8 00 00 00 00 00 fc ff df 49 c1 ee 03 49 01 c6 e8 12 30 ab ff f3 90 <41> 0f b6 06 84 c0 74 08 3c 03 0f 8e d6 13 00 00 44 8b 2d 89 76 95
RSP: 0018:ffffc9000612fa28 EFLAGS: 00000246
RAX: 0000000000040000 RBX: 0000000000000040 RCX: ffffc900112bf000
RDX: 0000000000040000 RSI: ffffffff81cbd01e RDI: 0000000000000003
RBP: ffffc9000612fac8 R08: 0000000000000000 R09: ffffffff81cbd509
R10: ffffffff81cbd048 R11: 0000000000000000 R12: ffffc9000612fc7c
R13: 00000000000172b1 R14: fffffbfff16c28d8 R15: 0000000000000001
path_openat+0x183/0x2750 fs/namei.c:3554
do_filp_open+0x1aa/0x400 fs/namei.c:3586
do_sys_openat2+0x16d/0x4d0 fs/open.c:1212
do_sys_open fs/open.c:1228 [inline]
__do_sys_openat fs/open.c:1244 [inline]
__se_sys_openat fs/open.c:1239 [inline]
__x64_sys_openat+0x13f/0x1f0 fs/open.c:1239
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f6ea0250ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6e9d7c6188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6ea0363f60 RCX: 00007f6ea0250ae9
RDX: 0000000000004080 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 00007f6ea02aaf45 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc7da3940f R14: 00007f6e9d7c6300 R15: 0000000000022000
NMI backtrace for cpu 0
CPU: 0 PID: 32644 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
rcu_pending kernel/rcu/tree.c:3878 [inline]
rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597
update_process_times+0x16d/0x200 kernel/time/timer.c:1785
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
__sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:pie_calculate_probability+0x348/0x7c0 net/sched/sch_pie.c:398
Code: 85 ed 0f 8f 89 01 00 00 e8 85 de 23 fa 4c 89 e6 4c 89 ff e8 2a e6 23 fa 4d 39 e7 73 0d e8 70 de 23 fa 48 c7 43 20 00 00 00 00 63 de 23 fa 48 8b 2c 24 31 ff 4c 09 f5 48 89 ee e8 22 e5 23 fa
RSP: 0018:ffffc90000007c50 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88806ba09e60 RCX: 0000000000000100
RDX: ffff88807c438080 RSI: ffffffff875321c0 RDI: 0000000000000003
RBP: fffffff0a3da8872 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff875321b6 R11: 0000000000000000 R12: fffffff0a3da8872
R13: ffff88807b9a0b00 R14: 0000000000000000 R15: 0000000000000000
fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
expire_timers kernel/time/timer.c:1466 [inline]
__run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
__run_timers kernel/time/timer.c:1715 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:636
irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5608
Code: 64 a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc9000592fb50 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff92000b25f6c RCX: ffffffff815bc2bf
RDX: 1ffff1100f88715b RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8fd4aa0f
R10: fffffbfff1fa9541 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8b6146c8 R15: 0000000000000000
do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline]
do_write_seqcount_begin include/linux/seqlock.h:545 [inline]
write_seqlock include/linux/seqlock.h:891 [inline]
lock_mount_hash fs/namespace.c:102 [inline]
mntput_no_expire+0x2a6/0xcd0 fs/namespace.c:1178
mntput+0x67/0x90 fs/namespace.c:1233
simple_recursive_removal+0x44f/0x760 fs/libfs.c:296
debugfs_remove fs/debugfs/inode.c:732 [inline]
debugfs_remove+0x59/0x80 fs/debugfs/inode.c:726
blk_mq_debugfs_unregister_hctx+0x34/0xa0 block/blk-mq-debugfs.c:771
blk_mq_exit_hw_queues block/blk-mq.c:3034 [inline]
blk_mq_exit_queue+0x197/0x550 block/blk-mq.c:3686
blk_cleanup_queue+0x15e/0x210 block/blk-core.c:367
blk_cleanup_disk+0x33/0x80 block/genhd.c:1378
loop_remove+0x60/0xf0 drivers/block/loop.c:2082
loop_control_remove drivers/block/loop.c:2138 [inline]
loop_control_ioctl+0x445/0x4a0 drivers/block/loop.c:2176
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8914fb6ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f891252c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f89150c9f60 RCX: 00007f8914fb6ae9
RDX: 000000000000000b RSI: 0000000000004c81 RDI: 0000000000000005
RBP: 00007f8915010f45 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffff28cdd6f R14: 00007f891252c300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: 48 89 fa mov %rdi,%rdx
3: 48 c1 ea 03 shr $0x3,%rdx
7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
b: 75 51 jne 0x5e
d: 48 03 1c ed a0 78 34 add -0x74cb8760(,%rbp,8),%rbx
14: 8b
15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
1c: fc ff df
1f: 48 89 da mov %rbx,%rdx
22: 48 c1 ea 03 shr $0x3,%rdx
26: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx
* 2a: 48 89 d8 mov %rbx,%rax <-- trapping instruction
2d: 83 e0 07 and $0x7,%eax
30: 83 c0 03 add $0x3,%eax
33: 38 d0 cmp %dl,%al
35: 7c 04 jl 0x3b
37: 84 d2 test %dl,%dl
39: 75 19 jne 0x54
3b: 8b 03 mov (%rbx),%eax
3d: 83 e0 01 and $0x1,%eax