Commit f5c2ec28 authored Nov 25, 2022 by Johannes Berg Committed by Greg Kroah-Hartman Dec 08, 2022

wifi: cfg80211: fix buffer overflow in elem comparison



[ Upstream commit 9f16b5c82a025cd4c864737409234ddc44fb166a ]

For vendor elements, the code here assumes that 5 octets
are present without checking. Since the element itself is
already checked to fit, we only need to check the length.

Reported-and-tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 0b8fb823 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 06785845

net/wireless/scan.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -291,7 +291,8 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
		* determine if they are the same ie.
		*/
		if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) {
		if (!memcmp(tmp_old + 2, tmp + 2, 5)) {
		if (tmp_old[1] >= 5 && tmp[1] >= 5 &&
		!memcmp(tmp_old + 2, tmp + 2, 5)) {
		/* same vendor ie, copy from
		* subelement
		*/