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

[Greg KH]

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.

greg k-h