TDLS: Fix TDLS Setup Request processing in existing-peer cases

wpa_tdls_peer_free() ended up getting called after some of the
parameters from the TDLS Setup Request frame were copied into the struct
wpa_tdls_peer information. This could result in continuing with cleared
information in case the new exchange was the one that is used in
concurrent initialization case or if this is to re-negotiated an
existing TDLS link. The driver would not be provided with all the peer
capabilities correctly in such case.

Fix this by moving the existing_peer check to happen before the
information from the TDLS Setup Request frame is copied.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

src/rsn_supp/tdls.c

@@ -1464,6 +1464,52 @@ static int wpa_tdls_process_tpk_m1(struct wpa_sm *sm, const u8 *src_addr,
 	if (peer == NULL)
 		goto error;
 
+	/* If found, use existing entry instead of adding a new one;
+	 * how to handle the case where both ends initiate at the
+	 * same time? */
+	if (existing_peer) {
+		if (peer->tpk_success) {
+			wpa_printf(MSG_DEBUG, "TDLS: TDLS Setup Request while "
+				   "direct link is enabled - tear down the "
+				   "old link first");
+#if 0
+			/* TODO: Disabling the link would be more proper
+			 * operation here, but it seems to trigger a race with
+			 * some drivers handling the new request frame. */
+			wpa_sm_tdls_oper(sm, TDLS_DISABLE_LINK, src_addr);
+#else
+			if (sm->tdls_external_setup)
+				wpa_sm_tdls_oper(sm, TDLS_DISABLE_LINK,
+						 src_addr);
+			else
+				wpa_tdls_del_key(sm, peer);
+#endif
+			wpa_tdls_peer_free(sm, peer);
+		}
+
+		/*
+		 * An entry is already present, so check if we already sent a
+		 * TDLS Setup Request. If so, compare MAC addresses and let the
+		 * STA with the lower MAC address continue as the initiator.
+		 * The other negotiation is terminated.
+		 */
+		if (peer->initiator) {
+			if (os_memcmp(sm->own_addr, src_addr, ETH_ALEN) < 0) {
+				wpa_printf(MSG_DEBUG, "TDLS: Discard request "
+					   "from peer with higher address "
+					   MACSTR, MAC2STR(src_addr));
+				return -1;
+			} else {
+				wpa_printf(MSG_DEBUG, "TDLS: Accept request "
+					   "from peer with lower address "
+					   MACSTR " (terminate previously "
+					   "initiated negotiation",
+					   MAC2STR(src_addr));
+				wpa_tdls_disable_link(sm, peer->addr);
+			}
+		}
+	}
+
 	/* capability information */
 	peer->capability = WPA_GET_LE16(cpos);
 	cpos += 2;
@@ -1595,52 +1641,6 @@ static int wpa_tdls_process_tpk_m1(struct wpa_sm *sm, const u8 *src_addr,
 	}
 
 skip_rsn:
-	/* If found, use existing entry instead of adding a new one;
-	 * how to handle the case where both ends initiate at the
-	 * same time? */
-	if (existing_peer) {
-		if (peer->tpk_success) {
-			wpa_printf(MSG_DEBUG, "TDLS: TDLS Setup Request while "
-				   "direct link is enabled - tear down the "
-				   "old link first");
-#if 0
-			/* TODO: Disabling the link would be more proper
-			 * operation here, but it seems to trigger a race with
-			 * some drivers handling the new request frame. */
-			wpa_sm_tdls_oper(sm, TDLS_DISABLE_LINK, src_addr);
-#else
-			if (sm->tdls_external_setup)
-				wpa_sm_tdls_oper(sm, TDLS_DISABLE_LINK,
-						 src_addr);
-			else
-				wpa_tdls_del_key(sm, peer);
-#endif
-			wpa_tdls_peer_free(sm, peer);
-		}
-
-		/*
-		 * An entry is already present, so check if we already sent a
-		 * TDLS Setup Request. If so, compare MAC addresses and let the
-		 * STA with the lower MAC address continue as the initiator.
-		 * The other negotiation is terminated.
-		 */
-		if (peer->initiator) {
-			if (os_memcmp(sm->own_addr, src_addr, ETH_ALEN) < 0) {
-				wpa_printf(MSG_DEBUG, "TDLS: Discard request "
-					   "from peer with higher address "
-					   MACSTR, MAC2STR(src_addr));
-				return -1;
-			} else {
-				wpa_printf(MSG_DEBUG, "TDLS: Accept request "
-					   "from peer with lower address "
-					   MACSTR " (terminate previously "
-					   "initiated negotiation",
-					   MAC2STR(src_addr));
-				wpa_tdls_disable_link(sm, peer->addr);
-			}
-		}
-	}
-
 #ifdef CONFIG_TDLS_TESTING
 	if (tdls_testing & TDLS_TESTING_CONCURRENT_INIT) {
 		if (os_memcmp(sm->own_addr, peer->addr, ETH_ALEN) < 0) {