[Linux Kernel Bug][drivers/pktcdvd] INFO: task hung in __rq_qos_throttle

[Chenyuan Yang]

Dear Linux Developers for Packet writing,

We encountered several task hungs when testing the pktcdvd driver with
Syzkaller and our generated specifications, especially when using
`ioctl$PACKET_CTRL_CMD`.

I attached the reports (and C/syz reproducers) for two hungs "INFO:
task hung in add_transaction_credits" and "INFO: task hung in
__rq_qos_throttle", along with the config for the kernel.

Their reproducers are similar:
```
r0 = openat$KGPT_pktcdvd(0xffffffffffffff9c, &(0x7f0000000440), 0x2, 0x0)
ioctl$KGPT_PACKET_CTRL_CMD(r0, 0xc0185801, &(0x7f0000000180)={0x0,
0x0, 0x800, 0x0, 0x0, 0xa1bd})
```
```
r0 = openat$KGPT_pktcdvd(0xffffffffffffff9c, &(0x7f00000001c0), 0x2, 0x0)
ioctl$KGPT_PACKET_CTRL_CMD(r0, 0xc0185801, &(0x7f0000000080)={0x0, 0x0, 0x800})
```


If you have any questions or require more information, please feel
free to contact us.

Reported-by: Chenyuan Yang <chenyuan0y@xxxxxxxxx>

Best,
Chenyuan

Attachment: task-hung-add_transaction_credits.report
Description: Binary data

Attachment: task-hung-__rq_qos_throttle.report
Description: Binary data

Attachment: config
Description: Binary data