On Sun, Jul 03, 2022 at 01:57:25PM +0900, Dae R. Jeong wrote:
> Hello,
>
> We observed an issue "INFO: task hung in blk_trace_remove" during
> fuzzing.
We also observed a similar issue "INFO: task hung in
blk_trace_setup". At this point, we don't know whether these two
issues are caused by the same reason.
Unfortunately, we have not found a reproducer for this crash. We will
inform you if we have any update.
The crash information is attached at the end of this email.
Best regards,
Dae R. Jeong
------
- Kernel commit:
92f20ff72066d
- Crash report:
INFO: task syz-executor.0:13708 blocked for more than 143 seconds.
Not tainted 5.19.0-rc3-32288-g0f3b08299494 #15
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:26560 pid:13708 ppid: 6772 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5146 [inline]
__schedule+0x96c/0x10f0 kernel/sched/core.c:6458
schedule+0xea/0x1b0 kernel/sched/core.c:6530
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589
__mutex_lock_common+0xe0f/0x25e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
blk_trace_setup+0xa9/0x1b0 kernel/trace/blktrace.c:616
sg_ioctl_common drivers/scsi/sg.c:1122 [inline]
sg_ioctl+0x1b61/0x4000 drivers/scsi/sg.c:1164
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0x129/0x1c0 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4e/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x478dc9
RSP: 002b:00007f5dde784be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000077d4a0 RCX: 0000000000478dc9
RDX: 0000000020000340 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000077d4a8
R13: 000000000077d4ac R14: 000000000077d4a0 R15: 00007ffdfb78c900
</TASK>
INFO: task syz-executor.0:13709 blocked for more than 143 seconds.
Not tainted 5.19.0-rc3-32288-g0f3b08299494 #15
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:26608 pid:13709 ppid: 6772 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5146 [inline]
__schedule+0x96c/0x10f0 kernel/sched/core.c:6458
schedule+0xea/0x1b0 kernel/sched/core.c:6530
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6589
__mutex_lock_common+0xe0f/0x25e0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
blk_trace_setup+0xa9/0x1b0 kernel/trace/blktrace.c:616
sg_ioctl_common drivers/scsi/sg.c:1122 [inline]
sg_ioctl+0x1b61/0x4000 drivers/scsi/sg.c:1164
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0x129/0x1c0 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4e/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x478dc9
RSP: 002b:00007f5dde763be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000077e9c0 RCX: 0000000000478dc9
RDX: 00000000200003c0 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000077e9c8
R13: 000000000077e9cc R14: 000000000077e9c0 R15: 00007ffdfb78c900
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/40:
#0: ffffffff9071a3e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by systemd-journal/3025:
#0: ffff8880b933bb58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x110 kernel/sched/core.c:544
1 lock held by in:imklog/6630:
#0: ffff88801c6e40e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2f3/0x430 fs/file.c:1036
2 locks held by syz-executor.0/13707:
1 lock held by syz-executor.0/13708:
#0: ffff88814c195ff8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xa9/0x1b0 kernel/trace/blktrace.c:616
1 lock held by syz-executor.0/13709:
#0: ffff88814c195ff8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xa9/0x1b0 kernel/trace/blktrace.c:616
