INFO: task kworker/u4:5:1325 blocked for more than 143 seconds.
Not tainted 5.16.0-rc1-next-20211116-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:5 state:D stack:24464 pid: 1325 ppid: 2 flags:0x00004000
Workqueue: nbd-del nbd_dev_remove_work
Call Trace:
context_switch kernel/sched/core.c:4987 [inline]
__schedule+0xa9a/0x4940 kernel/sched/core.c:6268
schedule+0xd2/0x260 kernel/sched/core.c:6341
blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178
del_gendisk+0x598/0x860 block/genhd.c:623
nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8bb83b20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
2 locks held by kworker/u4:5/1325:
#0: ffff88801a54c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88801a54c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88801a54c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff88801a54c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff88801a54c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff88801a54c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc90005ad7db0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
1 lock held by systemd-journal/2955:
1 lock held by systemd-udevd/2972:
1 lock held by in:imklog/6221:
#0: ffff88807b67a0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
3 locks held by syz-executor.0/6552:
1 lock held by syz-executor.3/6558:
3 locks held by kworker/u4:7/11585:
1 lock held by syz-executor.2/26696:
#0: ffffffff8bb8cdb0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x440 kernel/rcu/tree.c:3985
1 lock held by syz-executor.5/26712:
1 lock held by syz-executor.5/26714:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-next-20211116-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:111
nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline]
watchdog+0xcb7/0xed0 kernel/hung_task.c:339
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2955 Comm: systemd-journal Not tainted 5.16.0-rc1-next-20211116-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mark_usage kernel/locking/lockdep.c:4486 [inline]
RIP: 0010:__lock_acquire+0x7b6/0x54a0 kernel/locking/lockdep.c:4981
Code: 49 8d 6c 24 22 41 0f b6 5c 24 21 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 0f b6 04 02 48 89 ea 83 e2 07 38 d0 7f 08 <84> c0 0f 85 da 38 00 00 84 db 41 0f b6 44 24 22 78 60 a8 03 0f 84
RSP: 0018:ffffc90001b2f730 EFLAGS: 00000093
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815ca1cc
RDX: 0000000000000002 RSI: 0000000000000008 RDI: ffff88807b520ab1
RBP: ffff88807b520ab2 R08: 0000000000000000 R09: ffffffff8ff77a1f
R10: 0000000000000001 R11: 000000000000002f R12: ffff88807b520a90
R13: ffff88807b520000 R14: 0000000000060000 R15: 0000000000000000
FS: 00007fc6538258c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7867dd7dd8 CR3: 000000002364b000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline]
set_root+0x3be/0x5b0 fs/namei.c:940
nd_jump_root+0x3c8/0x570 fs/namei.c:961
path_init+0x1020/0x1920 fs/namei.c:2359
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_open fs/open.c:1236 [inline]
__se_sys_open fs/open.c:1232 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1232
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: 0033:0x7fc652db4840
Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
RSP: 002b:00007fff961bcff8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fff961bd300 RCX: 00007fc652db4840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005595dad8c8f0
RBP: 000000000000000d R08: 000000000000ffc0 R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00005595dad7f040 R14: 00007fff961bd2c0 R15: 00005595dad8c4d0
----------------
Code disassembly (best guess):
0: 49 8d 6c 24 22 lea 0x22(%r12),%rbp
5: 41 0f b6 5c 24 21 movzbl 0x21(%r12),%ebx
b: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
12: fc ff df
15: 48 89 ea mov %rbp,%rdx
18: 48 c1 ea 03 shr $0x3,%rdx
1c: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax
20: 48 89 ea mov %rbp,%rdx
23: 83 e2 07 and $0x7,%edx
26: 38 d0 cmp %dl,%al
28: 7f 08 jg 0x32
* 2a: 84 c0 test %al,%al <-- trapping instruction
2c: 0f 85 da 38 00 00 jne 0x390c
32: 84 db test %bl,%bl
34: 41 0f b6 44 24 22 movzbl 0x22(%r12),%eax
3a: 78 60 js 0x9c
3c: a8 03 test $0x3,%al
3e: 0f .byte 0xf
3f: 84 .byte 0x84