Fix uninitialized slot array access during the upgrade.

Commit 29d0a77fa introduced fetching slot information from the old cluster
but didn't initialize the required array in all the code paths. So when
trying to access the array in verbose mode for the new cluster, it leads
to an uninitialized memory access.

Author: Vignesh C
Discussion: http://postgr.es/m/CALDaNm1tntGP5=CtMz=v+k3_PGv7kE9t6iWSgX-QiurAaFkhZw@mail.gmail.com

diff --git a/src/bin/pg_upgrade/info.c b/src/bin/pg_upgrade/info.c
index 7f21d26fd2334763afb5bb9e2182d9aef2d5b1be..4878aa22bfd9a11ab71ca084e30a7c1a2cbe97fd 100644 (file)
--- a/src/bin/pg_upgrade/info.c
+++ b/src/bin/pg_upgrade/info.c
@@ -408,7 +408,7 @@ get_db_infos(ClusterInfo *cluster)
        i_spclocation = PQfnumber(res, "spclocation");
 
        ntups = PQntuples(res);
-       dbinfos = (DbInfo *) pg_malloc(sizeof(DbInfo) * ntups);
+       dbinfos = (DbInfo *) pg_malloc0(sizeof(DbInfo) * ntups);
 
        for (tupnum = 0; tupnum < ntups; tupnum++)
        {
@@ -636,15 +636,11 @@ get_old_cluster_logical_slot_infos(DbInfo *dbinfo, bool live_check)
        PGconn     *conn;
        PGresult   *res;
        LogicalSlotInfo *slotinfos = NULL;
-       int                     num_slots = 0;
+       int                     num_slots;
 
        /* Logical slots can be migrated since PG17. */
        if (GET_MAJOR_VERSION(old_cluster.major_version) <= 1600)
-       {
-               dbinfo->slot_arr.slots = slotinfos;
-               dbinfo->slot_arr.nslots = num_slots;
                return;
-       }
 
        conn = connectToServer(&old_cluster, dbinfo->db_name);