INFO: task kworker/u4:17:10677 blocked for more than 144 seconds.
Not tainted 5.15.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:17 state:D stack:24360 pid:10677 ppid: 2 flags:0x00004000
Workqueue: nbd-del nbd_dev_remove_work
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
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: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
2 locks held by kswapd0/98:
1 lock held by in:imklog/6215:
2 locks held by agetty/6223:
#0: ffff88807c267098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
#1: ffffc900029882e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
2 locks held by kworker/u4:17/10677:
#0: ffff88801ac36138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88801ac36138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88801ac36138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff88801ac36138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff88801ac36138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff88801ac36138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9001ffbfdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
1 lock held by systemd-udevd/12526:
1 lock held by syz-executor.2/14319:
#0: ffff888075f5cc10 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: i_mmap_lock_write include/linux/fs.h:498 [inline]
#0: ffff888075f5cc10 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: unlink_file_vma+0x7d/0x110 mm/mmap.c:169
1 lock held by syz-executor.3/14320:
#0: ffff888075f5cc10 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: i_mmap_lock_write include/linux/fs.h:498 [inline]
#0: ffff888075f5cc10 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: unlink_file_vma+0x7d/0x110 mm/mmap.c:169
1 lock held by syz-executor.5/14318:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd 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_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xc1d/0xf50 kernel/hung_task.c:295
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: 9890 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
RIP: 0010:trace_sched_process_wait include/trace/events/sched.h:344 [inline]
RIP: 0010:do_wait+0xa3d/0xce0 kernel/exit.c:1493
Code: e9 cb fc ff ff e8 03 64 31 00 65 ff 05 0c ed bb 7e 48 c7 c0 80 3e 7d 8d 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <0f> 85 3f 01 00 00 48 8b 05 66 bb 36 0c e8 51 4c 1c 00 31 ff 89 c3
RSP: 0018:ffffc9000a76fc90 EFLAGS: 00000246
RAX: 1ffffffff1afa7d0 RBX: 0000000000000001 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff814682ed RDI: 0000000000000003
RBP: ffffc9000a76fd18 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff81467945 R11: 0000000000000000 R12: 1ffff920014edf9f
R13: 00007ffd774ee31c R14: 0000000000000004 R15: 0000000000000000
FS: 0000555555f4d400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f845d41f000 CR3: 000000007ad1d000 CR4: 0000000000350ee0
Call Trace:
kernel_wait4+0x14c/0x260 kernel/exit.c:1684
__do_sys_wait4+0x13f/0x150 kernel/exit.c:1712
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: 0033:0x7fb1e5365f87
Code: 89 7c 24 10 48 89 4c 24 18 e8 35 50 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 65 50 02 00 8b 44
RSP: 002b:00007ffd774ee290 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 0000000000003663 RCX: 00007fb1e5365f87
RDX: 0000000040000001 RSI: 00007ffd774ee31c RDI: 00000000ffffffff
RBP: 00007ffd774ee31c R08: 0000000000000000 R09: 00007ffd77584080
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 00000000002b1138 R14: 0000000000000003 R15: 00007ffd774ee380
----------------
Code disassembly (best guess):
0: e9 cb fc ff ff jmpq 0xfffffcd0
5: e8 03 64 31 00 callq 0x31640d
a: 65 ff 05 0c ed bb 7e incl %gs:0x7ebbed0c(%rip) # 0x7ebbed1d
11: 48 c7 c0 80 3e 7d 8d mov $0xffffffff8d7d3e80,%rax
18: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
1f: fc ff df
22: 48 c1 e8 03 shr $0x3,%rax
26: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1)
* 2a: 0f 85 3f 01 00 00 jne 0x16f <-- trapping instruction
30: 48 8b 05 66 bb 36 0c mov 0xc36bb66(%rip),%rax # 0xc36bb9d
37: e8 51 4c 1c 00 callq 0x1c4c8d
3c: 31 ff xor %edi,%edi
3e: 89 c3 mov %eax,%ebx