From 1fe44a86ff0ff483aa1f1332f2b08f431fa51ce8 Mon Sep 17 00:00:00 2001 From: Lachlan Hodges Date: Thu, 26 Jun 2025 21:51:18 +1000 Subject: [PATCH] wifi: cfg80211: fix S1G beacon head validation in nl80211 S1G beacons contain fixed length optional fields that precede the variable length elements, ensure we take this into account when validating the beacon. This particular case was missed in 1e1f706fc2ce ("wifi: cfg80211/mac80211: correctly parse S1G beacon optional elements"). Fixes: 1d47f1198d58 ("nl80211: correctly validate S1G beacon head") Signed-off-by: Lachlan Hodges Link: https://patch.msgid.link/20250626115118.68660-1-lachlan.hodges@morsemicro.com [shorten/reword subject] Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 85f139016da2..50202d170f3a 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -229,6 +229,7 @@ static int validate_beacon_head(const struct nlattr *attr, unsigned int len = nla_len(attr); const struct element *elem; const struct ieee80211_mgmt *mgmt = (void *)data; + const struct ieee80211_ext *ext; unsigned int fixedlen, hdrlen; bool s1g_bcn; @@ -237,8 +238,10 @@ static int validate_beacon_head(const struct nlattr *attr, s1g_bcn = ieee80211_is_s1g_beacon(mgmt->frame_control); if (s1g_bcn) { - fixedlen = offsetof(struct ieee80211_ext, - u.s1g_beacon.variable); + ext = (struct ieee80211_ext *)mgmt; + fixedlen = + offsetof(struct ieee80211_ext, u.s1g_beacon.variable) + + ieee80211_s1g_optional_len(ext->frame_control); hdrlen = offsetof(struct ieee80211_ext, u.s1g_beacon); } else { fixedlen = offsetof(struct ieee80211_mgmt, -- 2.25.1