On Thu, Sep 25, 2025 at 01:10:59PM +0800, Qingfang Deng wrote:

The TTY layer already serializes line discipline operations with
tty->ldisc_sem, so the extra disc_data_lock and refcnt in 6pack
are unnecessary.

Removing them simplifies the code and also resolves a lockdep warning
reported by syzbot. The warning did not indicate a real deadlock, since
the write-side lock was only taken in process context with hardirqs
disabled.

Reported-by: syzbot+5fd749c74105b0e1b302@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68c858b0.050a0220.3c6139.0d1c.GAE@google.com/ (local)
Signed-off-by: Qingfang Deng <dqfext@gmail.com>
---
v2: add Closes tag
 - https://lore.kernel.org/netdev/20250923060706.10232-1-dqfext@gmail.com/ (local)

Thanks!

Reviewed-by: Dan Carpenter <redacted>

regards,
dan carpenter