mwifiex: remove redundant TDLS setup action frame check and avoid leaks

The unwanted frame types are already handled in 'default' case
of the switch/case below.
The str_ptr is allocated but it can be leaked if the length check
fails in the REQUEST/RESP cases. Fix it by allocating sta_ptr
after the length checks.
Reported-by: NPaul Stewart <pstew@chromium.org>
Signed-off-by: NBing Zhao <bzhao@marvell.com>
Signed-off-by: NAvinash Patil <patila@marvell.com>
Signed-off-by: NPaul Stewart <pstew@chromium.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/tdls.c

@@ -781,6 +781,7 @@ void mwifiex_process_tdls_action_frame(struct mwifiex_private *priv,
 	struct mwifiex_sta_node *sta_ptr;
 	u8 *peer, *pos, *end;
 	u8 i, action, basic;
+	__le16 cap = 0;
 	int ie_len = 0;
 
 	if (len < (sizeof(struct ethhdr) + 3))
@@ -792,18 +793,9 @@ void mwifiex_process_tdls_action_frame(struct mwifiex_private *priv,
 
 	peer = buf + ETH_ALEN;
 	action = *(buf + sizeof(struct ethhdr) + 2);
-
-	/* just handle TDLS setup request/response/confirm */
-	if (action > WLAN_TDLS_SETUP_CONFIRM)
-		return;
-
 	dev_dbg(priv->adapter->dev,
 		"rx:tdls action: peer=%pM, action=%d\n", peer, action);
 
-	sta_ptr = mwifiex_add_sta_entry(priv, peer);
-	if (!sta_ptr)
-		return;
-
 	switch (action) {
 	case WLAN_TDLS_SETUP_REQUEST:
 		if (len < (sizeof(struct ethhdr) + TDLS_REQ_FIX_LEN))
@@ -811,7 +803,7 @@ void mwifiex_process_tdls_action_frame(struct mwifiex_private *priv,
 
 		pos = buf + sizeof(struct ethhdr) + 4;
 		/* payload 1+ category 1 + action 1 + dialog 1 */
-		sta_ptr->tdls_cap.capab = cpu_to_le16(*(u16 *)pos);
+		cap = cpu_to_le16(*(u16 *)pos);
 		ie_len = len - sizeof(struct ethhdr) - TDLS_REQ_FIX_LEN;
 		pos += 2;
 		break;
@@ -821,7 +813,7 @@ void mwifiex_process_tdls_action_frame(struct mwifiex_private *priv,
 			return;
 		/* payload 1+ category 1 + action 1 + dialog 1 + status code 2*/
 		pos = buf + sizeof(struct ethhdr) + 6;
-		sta_ptr->tdls_cap.capab = cpu_to_le16(*(u16 *)pos);
+		cap = cpu_to_le16(*(u16 *)pos);
 		ie_len = len - sizeof(struct ethhdr) - TDLS_RESP_FIX_LEN;
 		pos += 2;
 		break;
@@ -833,10 +825,16 @@ void mwifiex_process_tdls_action_frame(struct mwifiex_private *priv,
 		ie_len = len - sizeof(struct ethhdr) - TDLS_CONFIRM_FIX_LEN;
 		break;
 	default:
-		dev_warn(priv->adapter->dev, "Unknown TDLS frame type.\n");
+		dev_dbg(priv->adapter->dev, "Unknown TDLS frame type.\n");
 		return;
 	}
 
+	sta_ptr = mwifiex_add_sta_entry(priv, peer);
+	if (!sta_ptr)
+		return;
+
+	sta_ptr->tdls_cap.capab = cap;
+
 	for (end = pos + ie_len; pos + 1 < end; pos += 2 + pos[1]) {
 		if (pos + 2 + pos[1] > end)
 			break;