diff options
Diffstat (limited to 'tags/2.6.18-10/30047_ieee80211-underflow.patch')
| -rw-r--r-- | tags/2.6.18-10/30047_ieee80211-underflow.patch | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/tags/2.6.18-10/30047_ieee80211-underflow.patch b/tags/2.6.18-10/30047_ieee80211-underflow.patch new file mode 100644 index 0000000..53c733a --- /dev/null +++ b/tags/2.6.18-10/30047_ieee80211-underflow.patch @@ -0,0 +1,54 @@ +From: John W. Linville <linville@tuxdriver.com> +Date: Tue, 2 Oct 2007 04:03:54 +0000 (-0700) +Subject: [IEEE80211]: avoid integer underflow for runt rx frames +X-Git-Tag: kvm-47~34^2~42^2 +X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Favi%2Fkvm.git;a=commitdiff_plain;h=04045f98e0457aba7d4e6736f37eed189c48a5f7 + +[IEEE80211]: avoid integer underflow for runt rx frames + +Reported by Chris Evans <scarybeasts@gmail.com>: + +> 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 +> set. +> +> This leads to integer underflow and crash here: +> +> if (frag != 0) +> flen -= hdrlen; +> +> (flen is subsequently used as a memcpy length parameter). + +How about this? + +Signed-off-by: John W. Linville <linville@tuxdriver.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + +diff --git a/net/ieee80211/ieee80211_rx.c b/net/ieee80211/ieee80211_rx.c +index f2de2e4..6284c99 100644 +--- a/net/ieee80211/ieee80211_rx.c ++++ b/net/ieee80211/ieee80211_rx.c +@@ -366,6 +366,12 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb, + frag = WLAN_GET_SEQ_FRAG(sc); + hdrlen = ieee80211_get_hdrlen(fc); + ++ if (skb->len < hdrlen) { ++ printk(KERN_INFO "%s: invalid SKB length %d\n", ++ dev->name, skb->len); ++ goto rx_dropped; ++ } ++ + /* Put this code here so that we avoid duplicating it in all + * Rx paths. - Jean II */ + #ifdef CONFIG_WIRELESS_EXT |