Re: [PATCH AUTOSEL 4.19] wifi: cfg80211: wext: add extra SIOCSIWSCAN data check

From: Pavel Machek
Date: Wed Jul 10 2024 - 08:09:14 EST


On Wed 2024-07-10 12:24:55, Greg KH wrote:
> On Wed, Jul 10, 2024 at 12:04:15PM +0200, Pavel Machek wrote:
> > Hi!
> >
> > > [ Upstream commit 6ef09cdc5ba0f93826c09d810c141a8d103a80fc ]
> > >
> > > In 'cfg80211_wext_siwscan()', add extra check whether number of
> > > channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed
> > > IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise.
> >
> > This results in very confusing code in 4.19 at least. It should goto
> > out for consistency, exploting kfree(NULL) to be nop. Ok, not sure we
> > care...
>
> kfree(NULL) is always supposed to be a nop, we have relied on that for
> decades, that's not an issue anywhere.

Take a look at the code, especially after this patch is applied.

BR,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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