mac80211: fix HT information element parsing

There's no checking that the HT IEs are of the right length
which can be used by an attacker to cause an out-of-bounds
access by sending a too short HT information/capability IE.
Fix it by simply pretending those IEs didn't exist when too
short.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2008-10-07 19:31:17 +02:00 committed by John W. Linville
parent 3eadd751eb
commit 09914813da
3 changed files with 6 additions and 11 deletions

View file

@ -816,8 +816,8 @@ struct ieee802_11_elems {
u8 *ext_supp_rates;
u8 *wmm_info;
u8 *wmm_param;
u8 *ht_cap_elem;
u8 *ht_info_elem;
struct ieee80211_ht_cap *ht_cap_elem;
struct ieee80211_ht_addt_info *ht_info_elem;
u8 *mesh_config;
u8 *mesh_id;
u8 *peer_link;
@ -844,8 +844,6 @@ struct ieee802_11_elems {
u8 ext_supp_rates_len;
u8 wmm_info_len;
u8 wmm_param_len;
u8 ht_cap_elem_len;
u8 ht_info_elem_len;
u8 mesh_config_len;
u8 mesh_id_len;
u8 peer_link_len;

View file

@ -1348,10 +1348,8 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
(ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
struct ieee80211_ht_bss_info bss_info;
ieee80211_ht_cap_ie_to_ht_info(
(struct ieee80211_ht_cap *)
elems.ht_cap_elem, &sta->sta.ht_info);
ieee80211_ht_addt_info_ie_to_ht_bss_info(
(struct ieee80211_ht_addt_info *)
elems.ht_info_elem, &bss_info);
ieee80211_handle_ht(local, 1, &sta->sta.ht_info, &bss_info);
}
@ -1709,7 +1707,6 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
struct ieee80211_ht_bss_info bss_info;
ieee80211_ht_addt_info_ie_to_ht_bss_info(
(struct ieee80211_ht_addt_info *)
elems.ht_info_elem, &bss_info);
changed |= ieee80211_handle_ht(local, 1, &conf->ht_conf,
&bss_info);

View file

@ -529,12 +529,12 @@ void ieee802_11_parse_elems(u8 *start, size_t len,
elems->ext_supp_rates_len = elen;
break;
case WLAN_EID_HT_CAPABILITY:
elems->ht_cap_elem = pos;
elems->ht_cap_elem_len = elen;
if (elen >= sizeof(struct ieee80211_ht_cap))
elems->ht_cap_elem = (void *)pos;
break;
case WLAN_EID_HT_EXTRA_INFO:
elems->ht_info_elem = pos;
elems->ht_info_elem_len = elen;
if (elen >= sizeof(struct ieee80211_ht_addt_info))
elems->ht_info_elem = (void *)pos;
break;
case WLAN_EID_MESH_ID:
elems->mesh_id = pos;