Red Hat Bugzilla – Bug 346341
CVE-2007-4997 kernel ieee80211 off-by-two integer underflow
Last modified: 2016-03-04 05:38:43 EST
Common Vulnerabilities and Exposures assigned an identifier CVE-2007-4997 to the following vulnerability:
** RESERVED ** This candidate has been reserved by an organization or individual that will use it when announcing a new security problem. When the candidate has been publicized, the details for this candidate will be provided.
Chris Evans discovered that a malicious 80211 frame can crash machine if certain
drivers, chipsets, and firmware is in use.
eported by Chris Evans <firstname.lastname@example.org>:
> The summary is that an evil 80211 frame can crash out a victim's
> machine. It only applies to drivers using the 80211 wireless code, and
> only then to certain drivers (and even then depends on a card's
> firmware not dropping a dubious packet). I must confess I'm not
> keeping track of Linux wireless support, and the different protocol
> stacks etc.
> Details are as follows:
> ieee80211_rx() does not explicitly check that "skb->len >= hdrlen".
> There are other skb->len checks, but not enough to prevent a subtle
> off-by-two error if the frame has the IEEE80211_STYPE_QOS_DATA flag
> This leads to integer underflow and crash here:
> if (frag != 0)
> flen -= hdrlen;
> (flen is subsequently used as a memcpy length parameter).
Red Hat would like to credit Chris Evans for reporting this issue.
I should not be on this bug.
Now also public at http://scary.beasts.org/security/CESA-2007-007.html