mac80211: fix action frame length checks

The action frame length checks are one too small, there's not just
an action code as the comment makes you believe, there's a category
code too, and the category code is required in each action frame
(hence part of IEEE80211_MIN_ACTION_SIZE).

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ae97d7e9945d..eb1832aa1fe5 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -60,7 +60,7 @@
 
 #define ERP_INFO_USE_PROTECTION BIT(1)
 
-/* mgmt header + 1 byte action code */
+/* mgmt header + 1 byte category code */
 #define IEEE80211_MIN_ACTION_SIZE (24 + 1)
 
 #define IEEE80211_ADDBA_PARAM_POLICY_MASK 0x0002
@@ -2988,7 +2988,8 @@ static void ieee80211_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
 {
         struct ieee80211_local *local = sdata->local;
 
-        if (len < IEEE80211_MIN_ACTION_SIZE)
+        /* all categories we currently handle have action_code */
+        if (len < IEEE80211_MIN_ACTION_SIZE + 1)
                 return;
 
         switch (mgmt->u.action.category) {