mac80211: validate TIM IE length (redux)
The TIM IE must not be shorter than 4 bytes, so verify that
when parsing it and use the proper type. To ease that adjust
struct ieee80211_tim_ie to have a virtual bitmap of size
at least 1.
Also check that the TIM IE is actually present before trying
to parse it!
Because other people may need the function, make it a static
inline in ieee80211.h.
(The original "mac80211: validate TIM IE length" was a minimal fix for
2.6.30. This purports to be the full, correct fix. -- JWL)
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1124421..61876eb 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -588,8 +588,10 @@
elems->cf_params_len = elen;
break;
case WLAN_EID_TIM:
- elems->tim = pos;
- elems->tim_len = elen;
+ if (elen >= sizeof(struct ieee80211_tim_ie)) {
+ elems->tim = (void *)pos;
+ elems->tim_len = elen;
+ }
break;
case WLAN_EID_IBSS_PARAMS:
elems->ibss_params = pos;