ctdb-tests: fix mem leak in ltdb_fetch

Direct leak of 256 byte(s) in 8 object(s) allocated from:
    #0 0x7f11b90d9c08 in __interceptor_malloc (/lib64/libasan.so.5+0xefc08)
    #1 0x7f11b8f395df in tdb_alloc_read ../../../lib/tdb/common/io.c:696
    #2 0x7f11b8f290ee in _tdb_fetch ../../../lib/tdb/common/tdb.c:274
    #3 0x7f11b8f29379 in tdb_fetch ../../../lib/tdb/common/tdb.c:283
    #4 0x473ecc in ltdb_fetch ../../tests/src/fake_ctdbd.c:904
    #5 0x478b40 in ltdb_transaction_update ../../tests/src/fake_ctdbd.c:993
    #6 0x41fef2 in ctdb_rec_buffer_traverse ../../protocol/protocol_types.c:1656
    #7 0x48108b in ltdb_transaction ../../tests/src/fake_ctdbd.c:1026
    #8 0x48108b in control_trans3_commit ../../tests/src/fake_ctdbd.c:2878
    #9 0x48108b in client_process_control ../../tests/src/fake_ctdbd.c:4147
    #10 0x48108b in client_process_packet ../../tests/src/fake_ctdbd.c:3839
    #11 0x4847f5 in client_read_handler ../../tests/src/fake_ctdbd.c:3806
    #12 0x44f620 in comm_read_done ../../common/comm.c:208
    #13 0x7f11b8f94fe8 in _tevent_req_notify_callback ../../../lib/tevent/tevent_req.c:141
    #14 0x7f11b8f951fd in tevent_req_finish ../../../lib/tevent/tevent_req.c:193
    #15 0x7f11b8f95265 in _tevent_req_done ../../../lib/tevent/tevent_req.c:199
    #16 0x44e876 in pkt_read_handler ../../common/pkt_read.c:133
    #17 0x44f315 in comm_fd_handler ../../common/comm.c:412
    #18 0x7f11b8f92896 in tevent_common_invoke_fd_handler ../../../lib/tevent/tevent_fd.c:138
    #19 0x7f11b8fa6937 in epoll_event_loop ../../../lib/tevent/tevent_epoll.c:736
    #20 0x7f11b8fa6937 in epoll_event_loop_once ../../../lib/tevent/tevent_epoll.c:937
    #21 0x7f11b8f9f53e in std_event_loop_once ../../../lib/tevent/tevent_standard.c:110
    #22 0x7f11b8f90f34 in _tevent_loop_once ../../../lib/tevent/tevent.c:772
    #23 0x7f11b8f955f1 in tevent_req_poll ../../../lib/tevent/tevent_req.c:300
    #24 0x485a04 in start_server ../../tests/src/fake_ctdbd.c:4450
    #25 0x485a04 in main ../../tests/src/fake_ctdbd.c:4544
    #26 0x7f11b8c60412 in __libc_start_main (/lib64/libc.so.6+0x24412)

Signed-off-by: Swen Schillig <swen@linux.ibm.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Martin Schwenke <martin@meltin.net>

Autobuild-User(master): Martin Schwenke <martins@samba.org>
Autobuild-Date(master): Mon Aug 26 10:19:30 UTC 2019 on sn-devel-184

ctdb/tests/src/fake_ctdbd.c

@@ -927,8 +927,10 @@ static int ltdb_fetch(struct database *db, TDB_DATA key,
 	data->dptr = talloc_memdup(mem_ctx,
 				   rec.dptr + ctdb_ltdb_header_len(header),
 				   data->dsize);
+
+	free(rec.dptr);
+
 	if (data->dptr == NULL) {
-		free(rec.dptr);
 		return ENOMEM;
 	}