From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 27 Jun 2019 15:57:10 +0000 (-0400)
Subject: Fix use-after-free introduced in 55ed3defc966
X-Git-Tag: REL_11_5~65
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e4f2d4fe9269c3c9c33f5182d4c3c90f99587fb4;p=postgresql

Fix use-after-free introduced in 55ed3defc966

Evidenced by failure under RELCACHE_FORCE_RELEASE (buildfarm member
prion).

Author: Amit Langote
Discussion: https://postgr.es/m/CA+HiwqGV=k_Eh4jBiQw66ivvdG+EUkrEYeHTYL1SvDj_YOYV0g@mail.gmail.com
---

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 11370c6590..1faaaf625d 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -896,13 +896,11 @@ DefineIndex(Oid relationId,
 
 			memcpy(part_oids, partdesc->oids, sizeof(Oid) * nparts);
 
-			parentDesc = CreateTupleDescCopy(RelationGetDescr(rel));
+			parentDesc = RelationGetDescr(rel);
 			opfamOids = palloc(sizeof(Oid) * numberOfKeyAttributes);
 			for (i = 0; i < numberOfKeyAttributes; i++)
 				opfamOids[i] = get_opclass_family(classObjectId[i]);
 
-			heap_close(rel, NoLock);
-
 			/*
 			 * For each partition, scan all existing indexes; if one matches
 			 * our index definition and is not already attached to some other
@@ -1100,13 +1098,12 @@ DefineIndex(Oid relationId,
 				heap_freetuple(newtup);
 			}
 		}
-		else
-			heap_close(rel, NoLock);
 
 		/*
 		 * Indexes on partitioned tables are not themselves built, so we're
 		 * done here.
 		 */
+		heap_close(rel, NoLock);
 		return address;
 	}