INFO: task kworker/u4:1:1116 blocked for more than 143 seconds.
Not tainted 5.16.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1 state:D stack:24496 pid: 1116 ppid: 2 flags:0x00004000
Workqueue: nbd-del nbd_dev_remove_work
Call Trace:
context_switch kernel/sched/core.c:4972 [inline]
__schedule+0xa9a/0x4940 kernel/sched/core.c:6253
schedule+0xd2/0x260 kernel/sched/core.c:6326
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: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
1 lock held by systemd-udevd/2969:
1 lock held by in:imklog/6192:
#0: ffff888022899c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
2 locks held by kworker/u4:1/1116:
#0: ffff88801a89c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88801a89c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88801a89c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff88801a89c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff88801a89c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff88801a89c938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9000417fdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
3 locks held by kworker/1:0/16132:
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9000b0cfdb0 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
#2: ffffffff8bb8ce68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#2: ffffffff8bb8ce68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fa/0x620 kernel/rcu/tree_exp.h:836
2 locks held by kworker/1:23/16153:
#0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9000b4ffdb0 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
2 locks held by systemd-udevd/30414:
1 lock held by syz-executor.5/30431:
5 locks held by syz-executor.5/30434:
1 lock held by syz-executor.1/30479:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-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: 30434 Comm: syz-executor.5 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3694 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3714 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3769 [inline]
RIP: 0010:__lock_acquire+0x166d/0x54a0 kernel/locking/lockdep.c:5027
Code: 46 86 c8 61 49 0f af ef 48 c1 ed 30 48 8d 04 ed 60 69 ee 8f 48 89 c2 48 89 44 24 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 10 3b 00 00 48 8b 1c ed 60 69 ee 8f 48 85 db 74
RSP: 0018:ffffc9000286f568 EFLAGS: 00000012
RAX: dffffc0000000000 RBX: 00000000000000a5 RCX: ffffffff815cb15f
RDX: 1ffffffff1fdf3ad RSI: 0000000000000008 RDI: ffffffff8ff76a10
RBP: 0000000000002681 R08: 0000000000000000 R09: ffffffff8ff76a17
R10: fffffbfff1feed42 R11: 0000000000000000 R12: ffff888042a5e1d8
R13: ffff888042a5d700 R14: 0000000000000000 R15: 001430ad0f110100
FS: 00007f5ae8158700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020800000 CR3: 000000004ee38000 CR4: 0000000000350ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
fs_reclaim_acquire mm/page_alloc.c:4552 [inline]
fs_reclaim_acquire+0xd2/0x160 mm/page_alloc.c:4543
might_alloc include/linux/sched/mm.h:227 [inline]
slab_pre_alloc_hook mm/slab.h:492 [inline]
slab_alloc_node mm/slub.c:3148 [inline]
slab_alloc mm/slub.c:3242 [inline]
kmem_cache_alloc+0x3e/0x3a0 mm/slub.c:3247
kmem_cache_zalloc include/linux/slab.h:714 [inline]
alloc_buffer_head+0x20/0x140 fs/buffer.c:3309
alloc_page_buffers+0x268/0x5f0 fs/buffer.c:832
create_empty_buffers+0x2c/0x800 fs/buffer.c:1560
ext4_block_write_begin+0xd1d/0x1140 fs/ext4/inode.c:1060
ext4_da_write_begin+0x3eb/0xad0 fs/ext4/inode.c:2966
generic_perform_write+0x205/0x510 mm/filemap.c:3756
ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269
ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681
call_write_iter include/linux/fs.h:2162 [inline]
new_sync_write+0x429/0x660 fs/read_write.c:503
vfs_write+0x7cd/0xae0 fs/read_write.c:590
ksys_write+0x12d/0x250 fs/read_write.c:643
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: 0033:0x7f5aeabe2ae9
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:00007f5ae8158188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5aeacf5f60 RCX: 00007f5aeabe2ae9
RDX: 000000000d4ba0ff RSI: 00000000200009c0 RDI: 0000000000000008
RBP: 00007f5aeac3cf6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc5a87a4ff R14: 00007f5ae8158300 R15: 0000000000022000
----------------
Code disassembly (best guess), 2 bytes skipped:
0: c8 61 49 0f enterq $0x4961,$0xf
4: af scas %es:(%rdi),%eax
5: ef out %eax,(%dx)
6: 48 c1 ed 30 shr $0x30,%rbp
a: 48 8d 04 ed 60 69 ee lea -0x701196a0(,%rbp,8),%rax
11: 8f
12: 48 89 c2 mov %rax,%rdx
15: 48 89 44 24 08 mov %rax,0x8(%rsp)
1a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
21: fc ff df
24: 48 c1 ea 03 shr $0x3,%rdx
* 28: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2c: 0f 85 10 3b 00 00 jne 0x3b42
32: 48 8b 1c ed 60 69 ee mov -0x701196a0(,%rbp,8),%rbx
39: 8f
3a: 48 85 db test %rbx,%rbx
3d: 74 .byte 0x74