dbus: Fix memory leak with Bonjour params for a P2P UPnP service

Using D-Bus, it is possible to add a valid UPnP service where 'query'
and 'response' are specified. In this case, memory for 'query' and
'response' is allocated but not used nor freed. Valgrind complains as
follows:

 42 bytes in 1 blocks are definitely lost in loss record 32 of 75
    at 0x484C214: calloc (vg_replace_malloc.c:1675)
    by 0x41C673: wpabuf_alloc (wpabuf.c:124)
    by 0x41C673: wpabuf_alloc_copy (wpabuf.c:162)
    by 0x54F41A: wpas_dbus_handler_p2p_add_service (dbus_new_handlers_p2p.c:2762)
    by 0x53B9A2: msg_method_handler (dbus_new_helpers.c:356)
    by 0x53B9A2: message_handler (dbus_new_helpers.c:412)
    by 0x4EAB4B8: dbus_connection_dispatch (in /usr/lib64/libdbus-1.so.3.19.13)
    by 0x5495DF: dispatch_data (dbus_common.c:37)
    by 0x5495DF: process_watch (dbus_common.c:73)
    by 0x5495DF: process_watch_read (dbus_common.c:89)
    by 0x41EE8E: eloop_sock_table_dispatch.part.0 (eloop.c:603)
    by 0x41FA46: eloop_sock_table_dispatch (eloop.c:597)
    by 0x41FA46: eloop_run (eloop.c:1233)
    by 0x56A3CE: wpa_supplicant_run (wpa_supplicant.c:8074)
    by 0x40DB06: main (main.c:393)

 49 bytes in 1 blocks are definitely lost in loss record 37 of 75
    at 0x484C214: calloc (vg_replace_malloc.c:1675)
    by 0x41C673: wpabuf_alloc (wpabuf.c:124)
    by 0x41C673: wpabuf_alloc_copy (wpabuf.c:162)
    by 0x54F348: wpas_dbus_handler_p2p_add_service (dbus_new_handlers_p2p.c:2755)
    by 0x53B9A2: msg_method_handler (dbus_new_helpers.c:356)
    by 0x53B9A2: message_handler (dbus_new_helpers.c:412)
    by 0x4EAB4B8: dbus_connection_dispatch (in /usr/lib64/libdbus-1.so.3.19.13)
    by 0x5495DF: dispatch_data (dbus_common.c:37)
    by 0x5495DF: process_watch (dbus_common.c:73)
    by 0x5495DF: process_watch_read (dbus_common.c:89)
    by 0x41EE8E: eloop_sock_table_dispatch.part.0 (eloop.c:603)
    by 0x41FA46: eloop_sock_table_dispatch (eloop.c:597)
    by 0x41FA46: eloop_run (eloop.c:1233)
    by 0x56A3CE: wpa_supplicant_run (wpa_supplicant.c:8074)
    by 0x40DB06: main (main.c:393)

Fix this ensuring that query and resp are freed both in the error and
non-error path of wpas_dbus_handler_p2p_add_service(). Also, add a test
in test_dbus.py to verify the correct behavior.

Signed-off-by: Davide Caratti <davide.caratti@gmail.com>

tests/hwsim/test_dbus.py

@@ -3406,12 +3406,22 @@ def test_dbus_p2p_service_discovery(dev, apdev):
     bonjour_query = dbus.ByteArray(binascii.unhexlify('0b5f6166706f766572746370c00c000c01'))
     bonjour_response = dbus.ByteArray(binascii.unhexlify('074578616d706c65c027'))
 
+    tests = [{'service_type': 'bonjour',
+              'query': bonjour_query,
+              'response': bonjour_response},
+             {'service_type': 'upnp',
+              'version': 0x10,
+              'service': 'uuid:6859dede-8574-59ab-9332-123456789012::upnp:rootdevice',
+              'query': bonjour_query,
+              'response': bonjour_response}]
+    for args in tests:
+        p2p.AddService(args)
+        p2p.FlushService()
+
     args = {'service_type': 'bonjour',
             'query': bonjour_query,
             'response': bonjour_response}
     p2p.AddService(args)
-    p2p.FlushService()
-    p2p.AddService(args)
 
     try:
         p2p.DeleteService(args)

wpa_supplicant/ctrl_iface.c

@@ -6740,6 +6740,7 @@ static int p2p_ctrl_service_add_bonjour(struct wpa_supplicant *wpa_s,
 	char *pos;
 	size_t len;
 	struct wpabuf *query, *resp;
+	int ret;
 
 	pos = os_strchr(cmd, ' ');
 	if (pos == NULL)
@@ -6753,34 +6754,28 @@ static int p2p_ctrl_service_add_bonjour(struct wpa_supplicant *wpa_s,
 	query = wpabuf_alloc(len);
 	if (query == NULL)
 		return -1;
-	if (hexstr2bin(cmd, wpabuf_put(query, len), len) < 0) {
+	ret = hexstr2bin(cmd, wpabuf_put(query, len), len);
-		wpabuf_free(query);
+	if (ret < 0)
-		return -1;
+		goto err_query;
-	}
+	ret = -1;
-
 	len = os_strlen(pos);
-	if (len & 1) {
+	if (len & 1)
-		wpabuf_free(query);
+		goto err_query;
-		return -1;
-	}
 	len /= 2;
 	resp = wpabuf_alloc(len);
-	if (resp == NULL) {
+	if (!resp)
-		wpabuf_free(query);
+		goto err_query;
-		return -1;
+	ret = hexstr2bin(pos, wpabuf_put(resp, len), len);
-	}
+	if (ret < 0)
-	if (hexstr2bin(pos, wpabuf_put(resp, len), len) < 0) {
+		goto err_resp;
-		wpabuf_free(query);
-		wpabuf_free(resp);
-		return -1;
-	}
 
-	if (wpas_p2p_service_add_bonjour(wpa_s, query, resp) < 0) {
+	ret = wpas_p2p_service_add_bonjour(wpa_s, query, resp);
-		wpabuf_free(query);
+
+err_resp:
 	wpabuf_free(resp);
-		return -1;
+err_query:
-	}
+	wpabuf_free(query);
-	return 0;
+	return ret;
 }
 
 

wpa_supplicant/dbus/dbus_new_handlers_p2p.c

@@ -2778,20 +2778,20 @@ DBusMessage * wpas_dbus_handler_p2p_add_service(DBusMessage *message,
 
 		if (wpas_p2p_service_add_bonjour(wpa_s, query, resp) < 0)
 			goto error;
-		query = NULL;
-		resp = NULL;
 	} else
 		goto error;
 
+out:
 	os_free(service);
+	wpabuf_free(query);
+	wpabuf_free(resp);
+
 	return reply;
 error_clear:
 	wpa_dbus_dict_entry_clear(&entry);
 error:
-	os_free(service);
+	reply = wpas_dbus_error_invalid_args(message, NULL);
-	wpabuf_free(query);
+	goto out;
-	wpabuf_free(resp);
-	return wpas_dbus_error_invalid_args(message, NULL);
 }
 
 

wpa_supplicant/p2p_supplicant_sd.c

@@ -1213,12 +1213,22 @@ int wpas_p2p_service_add_bonjour(struct wpa_supplicant *wpa_s,
 	bsrv = os_zalloc(sizeof(*bsrv));
 	if (bsrv == NULL)
 		return -1;
-	bsrv->query = query;
+	bsrv->query = wpabuf_dup(query);
-	bsrv->resp = resp;
+	if (!bsrv->query)
+		goto error_bsrv;
+	bsrv->resp = wpabuf_dup(resp);
+	if (!bsrv->resp)
+		goto error_query;
 	dl_list_add(&wpa_s->global->p2p_srv_bonjour, &bsrv->list);
 
 	wpas_p2p_sd_service_update(wpa_s);
 	return 0;
+
+error_query:
+	wpabuf_free(bsrv->query);
+error_bsrv:
+	os_free(bsrv);
+	return -1;
 }