P2P: Cleanup handling of unknown peer in PD Request processing

If a Provision Discovery Request is received for an unknown peer, a new
device entry is being added, but the flow continues without updating the
local p2p_device pointer, requiring to check the pointer value before
every access.

1. Change this, so once a device is added, the flow updates the local
   p2p_device pointer and avoids the checks later in the flow.
2. If the device is not known even after adding it, skip the processing,
   send the PD Response, and return.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>

src/p2p/p2p_pd.c

@@ -579,6 +579,17 @@ void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
 				   0)) {
 			p2p_dbg(p2p, "Provision Discovery Request add device failed "
 				MACSTR, MAC2STR(sa));
+			goto out;
+		}
+
+		if (!dev) {
+			dev = p2p_get_device(p2p, sa);
+			if (!dev) {
+				p2p_dbg(p2p,
+					"Provision Discovery device not found "
+					MACSTR, MAC2STR(sa));
+				goto out;
+			}
 		}
 	} else if (msg.wfd_subelems) {
 		wpabuf_free(dev->info.wfd_subelems);
@@ -610,37 +621,33 @@ void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
 		}
 	}
 
-	if (dev) {
-		dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
-				P2P_DEV_PD_PEER_KEYPAD |
-				P2P_DEV_PD_PEER_P2PS);
+	dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
+			P2P_DEV_PD_PEER_KEYPAD |
+			P2P_DEV_PD_PEER_P2PS);
 
-		/* Remove stale persistent groups */
-		if (p2p->cfg->remove_stale_groups) {
-			p2p->cfg->remove_stale_groups(
-				p2p->cfg->cb_ctx, dev->info.p2p_device_addr,
-				msg.persistent_dev,
-				msg.persistent_ssid, msg.persistent_ssid_len);
-		}
+	/* Remove stale persistent groups */
+	if (p2p->cfg->remove_stale_groups) {
+		p2p->cfg->remove_stale_groups(
+			p2p->cfg->cb_ctx, dev->info.p2p_device_addr,
+			msg.persistent_dev,
+			msg.persistent_ssid, msg.persistent_ssid_len);
 	}
+
 	if (msg.wps_config_methods & WPS_CONFIG_DISPLAY) {
 		p2p_dbg(p2p, "Peer " MACSTR
 			" requested us to show a PIN on display", MAC2STR(sa));
-		if (dev)
-			dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
+		dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
 		passwd_id = DEV_PW_USER_SPECIFIED;
 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
 		p2p_dbg(p2p, "Peer " MACSTR
 			" requested us to write its PIN using keypad",
 			MAC2STR(sa));
-		if (dev)
-			dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
+		dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
 		passwd_id = DEV_PW_REGISTRAR_SPECIFIED;
 	} else if (msg.wps_config_methods & WPS_CONFIG_P2PS) {
 		p2p_dbg(p2p, "Peer " MACSTR " requesting P2PS PIN",
 			MAC2STR(sa));
-		if (dev)
-			dev->flags |= P2P_DEV_PD_PEER_P2PS;
+		dev->flags |= P2P_DEV_PD_PEER_P2PS;
 		passwd_id = DEV_PW_P2PS_DEFAULT;
 	}
 
@@ -891,6 +898,11 @@ out:
 		wpabuf_free(resp);
 	}
 
+	if (!dev) {
+		p2p_parse_free(&msg);
+		return;
+	}
+
 	if (!p2p->cfg->p2ps_prov_complete) {
 		/* Don't emit anything */
 	} else if (msg.status && *msg.status != P2P_SC_SUCCESS &&
@@ -1028,7 +1040,7 @@ out:
 					msg.group_id, msg.group_id_len);
 	}
 
-	if (dev && reject == P2P_SC_SUCCESS) {
+	if (reject == P2P_SC_SUCCESS) {
 		switch (config_methods) {
 		case WPS_CONFIG_DISPLAY:
 			dev->wps_prov_info = WPS_CONFIG_KEYPAD;