Report a potential memory leak in PostgresSQL 14.1

Hi all,

I find a potential memory leak in PostgresSQL 14.1, which is in the function getPublicationTables (./src/bin/pg_dump/pg_dump.c).

Specifically, at line 4079, a memory chunk is allocated with pg_malloc() and assigned to 'pubrinfo' by employing the pg_malloc(). However, the function returns without freeing the memory and does not pass 'pubrinfo' to other functions. As a result, a memory leak problem is caused.

4045 void
4046 getPublicationTables(Archive *fout, TableInfo tblinfo[], int numTables)
4047 {
4048 PQExpBuffer query;
4049 PGresult *res;
4050 PublicationRelInfo *pubrinfo;
4051 DumpOptions *dopt = fout->dopt;
4052 int i_tableoid;
4053 int i_oid;
4054 int i_prpubid;
4055 int i_prrelid;
4056 int i,
4057 j,
4058 ntups;
4059
4060 if (dopt->no_publications || fout->remoteVersion < 100000)
4061 return;
4062
4063 query = createPQExpBuffer();
4064
4065 /* Collect all publication membership info. */
4066 appendPQExpBufferStr(query,
4067 "SELECT tableoid, oid, prpubid, prrelid "

4068 "FROM pg_catalog.pg_publication_rel");

4069 res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
4070
4071 ntups = PQntuples(res);
4072
4073 i_tableoid = PQfnumber(res, "tableoid");
4074 i_oid = PQfnumber(res, "oid");
4075 i_prpubid = PQfnumber(res, "prpubid");
4076 i_prrelid = PQfnumber(res, "prrelid");
4077
4078 /* this allocation may be more than we need */
4079 pubrinfo = pg_malloc(ntups * sizeof(PublicationRelInfo));
4080 j = 0;
4081
4082 for (i = 0; i < ntups; i++)
4083 {
4084 Oid prpubid = atooid(PQgetvalue(res, i, i_prpubid));
4085 Oid prrelid = atooid(PQgetvalue(res, i, i_prrelid));

4086 PublicationInfo *pubinfo;
4087 TableInfo *tbinfo;
4088
4089 /*
4090 * Ignore any entries for which we aren't interested in either the
4091 * publication or the rel.
4092 */
4093 pubinfo = findPublicationByOid(prpubid);
4094 if (pubinfo == NULL)
4095 continue;
4096 tbinfo = findTableByOid(prrelid);
4097 if (tbinfo == NULL)
4098 continue;
4099
4100 /*
4101 * Ignore publication membership of tables whose definitions are not
4102 * to be dumped.
4103 */
4104 if (!(tbinfo->dobj.dump & DUMP_COMPONENT_DEFINITION))
4105 continue;
4106

4107 /* OK, make a DumpableObject for this relationship */
4108 pubrinfo[j].dobj.objType = DO_PUBLICATION_REL;
4109 pubrinfo[j].dobj.catId.tableoid =
4110 atooid(PQgetvalue(res, i, i_tableoid));
4111 pubrinfo[j].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
4112 AssignDumpId(&pubrinfo[j].dobj);
4113 pubrinfo[j].dobj.namespace = tbinfo->dobj.namespace;
4114 pubrinfo[j].dobj.name = tbinfo->dobj.name;
4115 pubrinfo[j].publication = pubinfo;
4116 pubrinfo[j].pubtable = tbinfo;
4117
4118 /* Decide whether we want to dump it */
4119 selectDumpablePublicationObject(&(pubrinfo[j].dobj), fout);
4120
4121 j++;
4122 }
4123
4124 PQclear(res);
4125 destroyPQExpBuffer(query);
4126 }

I'm looking forward to your confirmation.

Best,

Wentao