INFO: task kworker/u4:5:25635 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/u4:5 state:D stack:23784 pid:25635 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: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
1 lock held by in:imklog/6215:
#0: ffff88807337ed70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
2 locks held by rs:main Q:Reg/6216:
2 locks held by kworker/u4:5/25635:
#0: ffff88801a4c9138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88801a4c9138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88801a4c9138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff88801a4c9138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff88801a4c9138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff88801a4c9138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9000b9a7db0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6216 Comm: rs:main Q:Reg Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:for_each_canary mm/kfence/core.c:351 [inline]
RIP: 0010:kfence_guarded_alloc mm/kfence/core.c:436 [inline]
RIP: 0010:__kfence_alloc+0xe86/0x13a0 mm/kfence/core.c:908
Code: 0f b6 04 18 41 83 f6 aa 38 d0 7f 08 84 c0 0f 85 19 03 00 00 45 88 34 24 49 83 c4 01 48 89 ef 4c 89 e6 e8 fd 10 b9 ff 4c 39 e5 <77> bb e8 83 0d b9 ff 0f 1f 44 00 00 e8 79 0d b9 ff 48 8b 04 24 48
RSP: 0018:ffffc9000c5e7358 EFLAGS: 00000216
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff88823bd0ea6b
RDX: 0000000000000000 RSI: ffff88807dbad700 RDI: 0000000000000003
RBP: ffff88823bd0f000 R08: ffff88823bd0f000 R09: 0000000000000030
R10: ffffffff81beda53 R11: 000000000000003f R12: ffff88823bd0ea6b
R13: ffff88823bd0e000 R14: 00000000ffffffa8 R15: ffff88823bd0e0c8
FS: 00007f5ae5dc3700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa64be8b010 CR3: 000000007c37c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
kfence_alloc include/linux/kfence.h:126 [inline]
slab_alloc_node mm/slub.c:3152 [inline]
slab_alloc mm/slub.c:3242 [inline]
kmem_cache_alloc+0x385/0x3a0 mm/slub.c:3247
mempool_alloc+0x146/0x350 mm/mempool.c:392
bio_alloc_bioset+0x2ff/0x4a0 block/bio.c:468
bio_alloc include/linux/bio.h:371 [inline]
submit_bh_wbc+0x1bc/0x7e0 fs/buffer.c:3026
submit_bh fs/buffer.c:3060 [inline]
__sync_dirty_buffer+0x16b/0x3f0 fs/buffer.c:3155
ext4_write_inode+0x574/0x630 fs/ext4/inode.c:5206
write_inode fs/fs-writeback.c:1469 [inline]
__writeback_single_inode+0xa97/0xff0 fs/fs-writeback.c:1674
writeback_single_inode+0x2c7/0x4d0 fs/fs-writeback.c:1729
sync_inode_metadata+0x93/0xd0 fs/fs-writeback.c:2749
ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
ext4_sync_file+0xa59/0xfd0 fs/ext4/fsync.c:170
vfs_fsync_range+0x13a/0x220 fs/sync.c:182
generic_write_sync include/linux/fs.h:2956 [inline]
ext4_buffered_write_iter+0x2d2/0x3b0 fs/ext4/file.c:277
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: 0033:0x7f5ae88071cd
Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f5ae5dc2590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5adc0099f0 RCX: 00007f5ae88071cd
RDX: 0000000000000088 RSI: 00007f5adc0099f0 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 656c6c616b7a7973
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f5adc009770
R13: 00007f5ae5dc25b0 R14: 000055c984d517c0 R15: 0000000000000088
----------------
Code disassembly (best guess):
0: 0f b6 04 18 movzbl (%rax,%rbx,1),%eax
4: 41 83 f6 aa xor $0xffffffaa,%r14d
8: 38 d0 cmp %dl,%al
a: 7f 08 jg 0x14
c: 84 c0 test %al,%al
e: 0f 85 19 03 00 00 jne 0x32d
14: 45 88 34 24 mov %r14b,(%r12)
18: 49 83 c4 01 add $0x1,%r12
1c: 48 89 ef mov %rbp,%rdi
1f: 4c 89 e6 mov %r12,%rsi
22: e8 fd 10 b9 ff callq 0xffb91124
27: 4c 39 e5 cmp %r12,%rbp
* 2a: 77 bb ja 0xffffffe7 <-- trapping instruction
2c: e8 83 0d b9 ff callq 0xffb90db4
31: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
36: e8 79 0d b9 ff callq 0xffb90db4
3b: 48 8b 04 24 mov (%rsp),%rax
3f: 48 rex.W