From 6873cc4416078202882691b424fcca5b5fb1a94d Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 24 Jul 2024 13:29:12 +0200 Subject: wifi: cfg80211: correct S1G beacon length calculation The minimum header length calculation (equivalent to the start of the elements) for the S1G long beacon erroneously required only up to the start of u.s1g_beacon rather than the start of u.s1g_beacon.variable. Fix that, and also shuffle the branches around a bit to not assign useless values that are overwritten later. Reported-by: syzbot+0f3afa93b91202f21939@syzkaller.appspotmail.com Fixes: 9eaffe5078ca ("cfg80211: convert S1G beacon to scan results") Link: https://patch.msgid.link/20240724132912.9662972db7c1.I8779675b5bbda4994cc66f876b6b87a2361c3c0b@changeid Signed-off-by: Johannes Berg --- net/wireless/scan.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index d99319d82205..64eeed82d43d 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -3178,8 +3178,7 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy, struct ieee80211_mgmt *mgmt, size_t len, gfp_t gfp) { - size_t min_hdr_len = offsetof(struct ieee80211_mgmt, - u.probe_resp.variable); + size_t min_hdr_len; struct ieee80211_ext *ext = NULL; enum cfg80211_bss_frame_type ftype; u16 beacon_interval; @@ -3202,10 +3201,16 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy, if (ieee80211_is_s1g_beacon(mgmt->frame_control)) { ext = (void *) mgmt; - min_hdr_len = offsetof(struct ieee80211_ext, u.s1g_beacon); if (ieee80211_is_s1g_short_beacon(mgmt->frame_control)) min_hdr_len = offsetof(struct ieee80211_ext, u.s1g_short_beacon.variable); + else + min_hdr_len = offsetof(struct ieee80211_ext, + u.s1g_beacon.variable); + } else { + /* same for beacons */ + min_hdr_len = offsetof(struct ieee80211_mgmt, + u.probe_resp.variable); } if (WARN_ON(len < min_hdr_len)) -- cgit v1.2.3-70-g09d2