From 1d47f1198d58117735edc6b8b1a687db47883f1e Mon Sep 17 00:00:00 2001 From: Thomas Pedersen Date: Tue, 8 Sep 2020 12:03:05 -0700 Subject: nl80211: correctly validate S1G beacon head The S1G beacon has a different header size than regular beacons, so adjust the beacon head validator. Signed-off-by: Thomas Pedersen Link: https://lore.kernel.org/r/20200908190323.15814-5-thomas@adapt-ip.com Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 17 +++++++++++++---- net/wireless/util.c | 5 +++++ 2 files changed, 18 insertions(+), 4 deletions(-) (limited to 'net/wireless') diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 7da4d84bcc1a..5d9d51cfc653 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -209,14 +209,23 @@ 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; - unsigned int fixedlen = offsetof(struct ieee80211_mgmt, - u.beacon.variable); + bool s1g_bcn = ieee80211_is_s1g_beacon(mgmt->frame_control); + unsigned int fixedlen, hdrlen; + + if (s1g_bcn) { + fixedlen = offsetof(struct ieee80211_ext, + u.s1g_beacon.variable); + hdrlen = offsetof(struct ieee80211_ext, u.s1g_beacon); + } else { + fixedlen = offsetof(struct ieee80211_mgmt, + u.beacon.variable); + hdrlen = offsetof(struct ieee80211_mgmt, u.beacon); + } if (len < fixedlen) goto err; - if (ieee80211_hdrlen(mgmt->frame_control) != - offsetof(struct ieee80211_mgmt, u.beacon)) + if (ieee80211_hdrlen(mgmt->frame_control) != hdrlen) goto err; data += fixedlen; diff --git a/net/wireless/util.c b/net/wireless/util.c index 4a9ff9ef513f..49e7c0cbbf62 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -399,6 +399,11 @@ unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc) { unsigned int hdrlen = 24; + if (ieee80211_is_ext(fc)) { + hdrlen = 4; + goto out; + } + if (ieee80211_is_data(fc)) { if (ieee80211_has_a4(fc)) hdrlen = 30; -- cgit v1.2.3