Re: [patch] rndis_wlan: add range check in del_key()

[Dan Carpenter <dan.carpenter@oracle.com>]

On Tue, Oct 18, 2011 at 08:54:47AM +0200, Johannes Berg wrote:
> On Tue, 2011-10-18 at 09:47 +0300, Dan Carpenter wrote:
> > Wifi drivers can have up to 6 keys but the rndis_wlan only has 4 so
> > it needs to have its own checks to make sure we don't go out of
> > bounds.  The add_key() function already checks but I added some
> > checks to del_key() and set_default_key().
> 
> Semantically, that shouldn't be possible unless it advertises support
> for WLAN_CIPHER_SUITE_AES_CMAC. Is there a bug in those checks?
> 

You know I'm a newbie at this networking...  I obviously had no idea
about WLAN_CIPHER_SUITE_AES_CMAC until you mentioned it.  I just
looked at the other implementations of del_key() etc and they checked
it.  Monkey see, monkey do.

My concern when I wrote this patch was places like __cfg80211_clear_ibss()
which just do:

	for (i = 0; i < 6; i++)
		rdev->ops->del_key(wdev->wiphy, dev, i, false, NULL);

That's what triggers the Smatch warning as well.  But as I said, I'm
quite a newbie at this code.

regards,
dan carpenter