Re: [PATCH] tty: n_gsm: add missing tty_kref_put

[Pavel Skripkin]

On 11/9/21 20:33, Jiri Slaby wrote:
> On 09. 11. 21, 11:39, Pavel Skripkin wrote:
> > My local syzbot instance hit memory leak in gsmld_attach_gsm(). The
> > reproducer injects allocation failure in tty_register_device(). After
> > this error only previous tty_register_device() calls unwinded, but not
> > tty_kref_get().
> >
> > It leads to tty_struct leak, because ->close() won't be called in case
> > of ->open() failure and nothing puts tty reference.
>
> I don't have time to check the n_gsm case now (like: are you talking
> about tty->open/close or file_ops->open/close -- they behave
> differently), but tty definitely calls close even if open fails.

Oh, I see now. I wasn't aware about this difference. Will do more 
detailed analysis of reported leak. Thank you for pointing it out!




With regards,
Pavel Skripkin