Re: [PATCH v2] hex2bin: fix access beyond string end

From: Andy Shevchenko
Date: Tue Apr 26 2022 - 09:18:16 EST


On Tue, Apr 26, 2022 at 08:07:44AM -0400, Mikulas Patocka wrote:
> On Tue, 26 Apr 2022, Andy Shevchenko wrote:
> > On Sun, Apr 24, 2022 at 10:48 PM Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote:
> > >
> > > If we pass too short string to "hex2bin" (and the string size without the
> > > terminating NUL character is even), "hex2bin" reads one byte after the
> > > terminating NUL character. This patch fixes it.
> > >
> > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
> > > Cc: stable@xxxxxxxxxxxxxxx
> >
> > You need to provide a Fixes tag.
>
> OK. Here I resend it with the "Fixes" tag.
>
> > And on top of that it would be nice to understand if we need to
> > support half-bytes, but in any case it's not a scope of the patch
> > right now.
>
> Do you think that there are any users who need this?

If my memory doesn't do any tricks with me, I have seen the patterns like
hex2bin() + hex_to_bin() in some places in the kernel.

--
With Best Regards,
Andy Shevchenko