Re: [PATCH v1 1/1] mac_pton: Don't access memory over expected length

From: Andrew Lunn
Date: Mon Oct 10 2022 - 16:46:00 EST


On Mon, Oct 10, 2022 at 11:29:37PM +0300, Andy Shevchenko wrote:
> On Mon, Oct 10, 2022 at 10:19:49PM +0200, Andrew Lunn wrote:
> > On Wed, Oct 05, 2022 at 07:43:01PM +0300, Andy Shevchenko wrote:
> > > The strlen() may go too far when estimating the length of
> > > the given string. In some cases it may go over the boundary
> > > and crash the system which is the case according to the commit
> > > 13a55372b64e ("ARM: orion5x: Revert commit 4904dbda41c8.").
> > >
> > > Rectify this by switching to strnlen() for the expected
> > > maximum length of the string.
> >
> > This seems like something which should have a fixes: tag, and be
> > against net, not net-next.
>
> I can (re-)send it that way. Just need a consensus by net maintainers.

I would probably do:

if (strnlen(s, maxlen) != maxlen)
return false;

I doubt anybody is removing leading zeros in MAC addresses.

Andrew