From b5ac0146492fc5c199de767e492be8a66471011a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 8 Apr 2021 14:28:27 +0200 Subject: [PATCH] cfg80211: check S1G beacon compat element length We need to check the length of this element so that we don't access data beyond its end. Fix that. Fixes: 9eaffe5078ca ("cfg80211: convert S1G beacon to scan results") Link: https://lore.kernel.org/r/20210408142826.f6f4525012de.I9fdeff0afdc683a6024e5ea49d2daa3cd2459d11@changeid Signed-off-by: Johannes Berg --- net/wireless/scan.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 019952d4fc7d..758eb7d2a706 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2352,14 +2352,16 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, return NULL; if (ext) { - struct ieee80211_s1g_bcn_compat_ie *compat; - u8 *ie; + const struct ieee80211_s1g_bcn_compat_ie *compat; + const struct element *elem; - ie = (void *)cfg80211_find_ie(WLAN_EID_S1G_BCN_COMPAT, - variable, ielen); - if (!ie) + elem = cfg80211_find_elem(WLAN_EID_S1G_BCN_COMPAT, + variable, ielen); + if (!elem) return NULL; - compat = (void *)(ie + 2); + if (elem->datalen < sizeof(*compat)) + return NULL; + compat = (void *)elem->data; bssid = ext->u.s1g_beacon.sa; capability = le16_to_cpu(compat->compat_info); beacon_int = le16_to_cpu(compat->beacon_int);