Re: [PATCH] misc: hpilo: Fix use-after-free in ilo_open

[Yoochan Lee]

Hi,

I haven't tested with a physical device cause I don't have a real device.
I found this bug through static analysis.

This type of bug is similar to [1] and [2].

And I'm sorry that my patch is incorrect.
It's my first time patching a Linux kernel myself.
So I'm not familiar with how to patch it well (For this reason, my
patches are referred to [1] and [2]).
Then, how should I patch it?

[1] https://lore.kernel.org/lkml/20220919040457.GA302681@ubuntu/
[2] https://lore.kernel.org/lkml/20220919101825.GA313940@ubuntu/

2022년 12월 31일 (토) 오후 6:58, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>님이 작성:
>
> On Sat, Dec 31, 2022 at 02:53:10PM +0900, Yoochan Lee wrote:
> > --- a/drivers/misc/hpilo.h
> > +++ b/drivers/misc/hpilo.h
> > @@ -62,6 +62,7 @@ struct ilo_hwinfo {
> >       spinlock_t fifo_lock;
> >
> >       struct cdev cdev;
> > +     struct kref refcnt;
>
> This is obviously incorrect, please never have 2 reference counts for
> the same structure.
>
> greg k-h