[PATCH v3 04/22] nl80211: correctly validate S1G beacon head
From: Thomas Pedersen <hidden>
Date: 2020-09-08 19:03:47
Subsystem:
802.11 (including cfg80211/nl80211), the rest · Maintainers:
Johannes Berg, Linus Torvalds
The S1G beacon has a different header size than regular beacons, so adjust the beacon head validator. Signed-off-by: Thomas Pedersen <redacted> --- net/wireless/nl80211.c | 16 +++++++++++++--- net/wireless/util.c | 5 +++++ 2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e408624018d5..8cf50bfedb01 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c@@ -209,14 +209,24 @@ 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)) + hdrlen) goto err; data += fixedlen;
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 7c5d5365a5eb..11822cd05a9f 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c@@ -397,6 +397,11 @@ 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;
--
2.20.1