nl80211: Validate NL80211_ATTR_KEY_SEQ length

Validate RSC (NL80211_ATTR_KEY_SEQ) length in nl80211/cfg80211 instead
of having to do this in all the drivers.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/util.c b/net/wireless/util.c
index beb226e..b94c860 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -181,5 +181,20 @@
 		return -EINVAL;
 	}
 
+	if (params->seq) {
+		switch (params->cipher) {
+		case WLAN_CIPHER_SUITE_WEP40:
+		case WLAN_CIPHER_SUITE_WEP104:
+			/* These ciphers do not use key sequence */
+			return -EINVAL;
+		case WLAN_CIPHER_SUITE_TKIP:
+		case WLAN_CIPHER_SUITE_CCMP:
+		case WLAN_CIPHER_SUITE_AES_CMAC:
+			if (params->seq_len != 6)
+				return -EINVAL;
+			break;
+		}
+	}
+
 	return 0;
 }