From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 19 Mar 2021 21:17:48 +0000 (-0400)
Subject: Fix use-after-ReleaseSysCache problem in ATExecAlterColumnType.
X-Git-Tag: REL_14_BETA1~522
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d00fbdc431192c3e429b3e91c43d364e5c7ba680;p=thirdparty%2Fpostgresql.git

Fix use-after-ReleaseSysCache problem in ATExecAlterColumnType.

Introduced by commit bbe0a81db69bd10bd166907c3701492a29aca294.

Per buildfarm member prion.
---

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ab89935ba73..9b2800bf5e2 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11953,8 +11953,6 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	attTup->attalign = tform->typalign;
 	attTup->attstorage = tform->typstorage;
 
-	ReleaseSysCache(typeTuple);
-
 	/* Setup attribute compression */
 	if (rel->rd_rel->relkind == RELKIND_RELATION ||
 		rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
@@ -11972,6 +11970,8 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	else
 		attTup->attcompression = InvalidCompressionMethod;
 
+	ReleaseSysCache(typeTuple);
+
 	CatalogTupleUpdate(attrelation, &heapTup->t_self, heapTup);
 
 	table_close(attrelation, RowExclusiveLock);