UPSTREAM: wifi: cfg80211: ensure length byte is present before access

commit 567e14e39e8f8c6997a1378bc3be615afca86063 upstream.

When iterating the elements here, ensure the length byte is
present before checking it to see if the entire element will
fit into the buffer.

Longer term, we should rewrite this code using the type-safe
element iteration macros that check all of this.

Bug: 254180332
Fixes: 0b8fb8235b ("cfg80211: Parsing of Multiple BSSID information in scanning")
Reported-by: Soenke Huster <shuster@seemoo.tu-darmstadt.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I6ece37c57ca56462566adbcac6def6b35dc5b799
This commit is contained in:
Johannes Berg
2022-09-29 21:50:44 +02:00
committed by Todd Kjos
parent 5f6b14356a
commit 2e8c292e35

View File

@@ -304,7 +304,8 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen);
tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie;
while (tmp_old + tmp_old[1] + 2 - ie <= ielen) {
while (tmp_old + 2 - ie <= ielen &&
tmp_old + tmp_old[1] + 2 - ie <= ielen) {
if (tmp_old[0] == 0) {
tmp_old++;
continue;
@@ -364,7 +365,8 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
* copied to new ie, skip ssid, capability, bssid-index ie
*/
tmp_new = sub_copy;
while (tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) {
while (tmp_new + 2 - sub_copy <= subie_len &&
tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) {
if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP ||
tmp_new[0] == WLAN_EID_SSID)) {
memcpy(pos, tmp_new, tmp_new[1] + 2);