Using D-Bus it is possible to request an invalid SD response where
"tlvs" is specified and there is an unknown key (e.g. "bar": "foo"). In
this case, "tlv" is allocated and then never used nor freed. Valgrind
complains as follows:
36 bytes in 1 blocks are definitely lost in loss record 20 of 74
at 0x484C214: calloc (vg_replace_malloc.c:1675)
by 0x41C673: wpabuf_alloc (wpabuf.c:124)
by 0x41C673: wpabuf_alloc_copy (wpabuf.c:162)
by 0x54FB94: wpas_dbus_handler_p2p_service_sd_res (dbus_new_handlers_p2p.c:3016)
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 0x56A3EE: 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_res(). Also, add a test case in
test_dbus.py to verify correct behavior.
Signed-off-by: Davide Caratti <davide.caratti@gmail.com>