From 28fa582f8372a6d73adb79f4d28fe997a08a23e0 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Wed, 24 Sep 2025 09:24:36 -0500
Subject: [PATCH v3 2/3] fix priv checks in index code

---
 src/backend/commands/indexcmds.c | 51 +++++++++++++++-----------------
 1 file changed, 24 insertions(+), 27 deletions(-)

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index ca2bde62e82..e4d05b5f8e6 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -2976,6 +2976,8 @@ RangeVarCallbackForReindexIndex(const RangeVar *relation,
 	struct ReindexIndexCallbackState *state = arg;
 	LOCKMODE	table_lockmode;
 	Oid			table_oid;
+	AclResult	aclresult;
+	bool		is_missing = false;
 
 	/*
 	 * Lock level here should match table lock in reindex_index() for
@@ -2985,12 +2987,8 @@ RangeVarCallbackForReindexIndex(const RangeVar *relation,
 	table_lockmode = (state->params.options & REINDEXOPT_CONCURRENTLY) != 0 ?
 		ShareUpdateExclusiveLock : ShareLock;
 
-	/*
-	 * If we previously locked some other index's heap, and the name we're
-	 * looking up no longer refers to that relation, release the now-useless
-	 * lock.
-	 */
-	if (relId != oldRelId && OidIsValid(oldRelId))
+	/* Unlock any previously locked heap. */
+	if (OidIsValid(state->locked_table_oid))
 	{
 		UnlockRelationOid(state->locked_table_oid, table_lockmode);
 		state->locked_table_oid = InvalidOid;
@@ -3014,30 +3012,29 @@ RangeVarCallbackForReindexIndex(const RangeVar *relation,
 				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 				 errmsg("\"%s\" is not an index", relation->relname)));
 
-	/* Check permissions */
+	/*
+	 * If the OID isn't valid, it means the index was concurrently dropped,
+	 * which is not a problem for us; just return normally.
+	 */
 	table_oid = IndexGetRelation(relId, true);
-	if (OidIsValid(table_oid))
-	{
-		AclResult	aclresult;
-
-		aclresult = pg_class_aclcheck(table_oid, GetUserId(), ACL_MAINTAIN);
-		if (aclresult != ACLCHECK_OK)
-			aclcheck_error(aclresult, OBJECT_INDEX, relation->relname);
-	}
+	if (!OidIsValid(table_oid))
+		return;
 
 	/* Lock heap before index to avoid deadlock. */
-	if (relId != oldRelId)
-	{
-		/*
-		 * If the OID isn't valid, it means the index was concurrently
-		 * dropped, which is not a problem for us; just return normally.
-		 */
-		if (OidIsValid(table_oid))
-		{
-			LockRelationOid(table_oid, table_lockmode);
-			state->locked_table_oid = table_oid;
-		}
-	}
+	LockRelationOid(table_oid, table_lockmode);
+	state->locked_table_oid = table_oid;
+
+	/*
+	 * Check permissions.  Since LockRelationOid() checks for invalidation
+	 * messages, the table might go missing here, too.  As before, this isn't
+	 * our problem; just return normally.
+	 */
+	aclresult = pg_class_aclcheck_ext(table_oid, GetUserId(),
+									  ACL_MAINTAIN, &is_missing);
+	if (is_missing)
+		return;
+	else if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_INDEX, relation->relname);
 }
 
 /*
-- 
2.39.5 (Apple Git-154)