[PATCH 1/3] P2P: fix memory leak in case dbus provides tlv in UPnP SD request

[Davide Caratti]

Using D-Bus it is possible to trigger a valid UPnP SD request where "tlv"
is specified: in this case "tlv" is allocated, and then not used nor freed.
Valgrind complains as follows:

 72 bytes in 2 blocks are definitely lost in loss record 46 of 68
    at 0x484C214: calloc (vg_replace_malloc.c:1675)
    by 0x41C673: wpabuf_alloc (wpabuf.c:124)
    by 0x41C673: wpabuf_alloc_copy (wpabuf.c:162)
    by 0x54F8B5: wpas_dbus_handler_p2p_service_sd_req (dbus_new_handlers_p2p.c:2928)
    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 it ensuring that "tlv" is freed, both in the error and non-error path
of wpas_dbus_handler_p2p_service_sd_req(). Also, add a test case in
test_dbus.py to verify correct behavior.

Signed-off-by: Davide Caratti <davide.caratti at gmail.com>
---
 tests/hwsim/test_dbus.py                    | 15 ++++++++++-----
 wpa_supplicant/dbus/dbus_new_handlers_p2p.c |  4 +---
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/tests/hwsim/test_dbus.py b/tests/hwsim/test_dbus.py
index 2c2a2e44a..28fa7197e 100644
--- a/tests/hwsim/test_dbus.py
+++ b/tests/hwsim/test_dbus.py
@@ -3501,11 +3501,16 @@ def test_dbus_p2p_service_discovery(dev, apdev):
         if "InvalidArgs" not in str(e):
             raise Exception("Unexpected error message for invalid AddService(): " + str(e))
 
-    args = {'service_type': 'upnp',
-            'version': 0x10,
-            'service': 'ssdp:foo'}
-    ref = p2p.ServiceDiscoveryRequest(args)
-    p2p.ServiceDiscoveryCancelRequest(ref)
+    tests= [{'service_type': 'upnp',
+             'version': 0x10,
+             'service': 'ssdp:foo'},
+            {'service_type': 'upnp',
+             'version': 0x10,
+             'service': 'ssdp:bar',
+             'tlv': dbus.ByteArray(b"\x02\x00\x00\x01")}]
+    for args in tests:
+        ref = p2p.ServiceDiscoveryRequest(args)
+        p2p.ServiceDiscoveryCancelRequest(ref)
 
     tests = [{'service_type': 'foo'},
              {'foo': 'bar'},
diff --git a/wpa_supplicant/dbus/dbus_new_handlers_p2p.c b/wpa_supplicant/dbus/dbus_new_handlers_p2p.c
index 16b2caad6..53495f2c3 100644
--- a/wpa_supplicant/dbus/dbus_new_handlers_p2p.c
+++ b/wpa_supplicant/dbus/dbus_new_handlers_p2p.c
@@ -2952,7 +2952,6 @@ DBusMessage * wpas_dbus_handler_p2p_service_sd_req(
 		if (tlv == NULL)
 			goto error;
 		ref = wpas_p2p_sd_request(wpa_s, addr, tlv);
-		wpabuf_free(tlv);
 	}
 
 	if (ref != 0) {
@@ -2964,14 +2963,13 @@ DBusMessage * wpas_dbus_handler_p2p_service_sd_req(
 			message, "Unable to send SD request");
 	}
 out:
+	wpabuf_free(tlv);
 	os_free(service);
 	os_free(peer_object_path);
 	return reply;
 error_clear:
 	wpa_dbus_dict_entry_clear(&entry);
 error:
-	if (tlv)
-		wpabuf_free(tlv);
 	reply = wpas_dbus_error_invalid_args(message, NULL);
 	goto out;
 }
-- 
2.44.0