Fix SerializeSnapshot not to overrun the allocated space.

robertmhaas · robertmhaas · commit 17b124d30317 · 2016-03-04T13:48:36.000-05:00
Rushabh Lathia
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
@@ -1515,7 +1515,7 @@ SerializeSnapshot(Snapshot snapshot, char *start_address)
 	 * snapshot taken during recovery; all the top-level XIDs are in subxip as
 	 * well in that case, so we mustn't lose them.
 	 */
-	if (snapshot->subxcnt > 0)
+	if (serialized_snapshot->subxcnt > 0)
 	{
 		Size		subxipoff = sizeof(SerializedSnapshotData) +
 		snapshot->xcnt * sizeof(TransactionId);

Original file line number	Diff line number	Diff line change
`@@ -1515,7 +1515,7 @@ SerializeSnapshot(Snapshot snapshot, char *start_address)`
`1515`	`1515`	`* snapshot taken during recovery; all the top-level XIDs are in subxip as`
`1516`	`1516`	`* well in that case, so we mustn't lose them.`
`1517`	`1517`	`*/`
`1518`		`- if (snapshot->subxcnt > 0)`
	`1518`	`+ if (serialized_snapshot->subxcnt > 0)`
`1519`	`1519`	`{`
`1520`	`1520`	`Size subxipoff = sizeof(SerializedSnapshotData) +`
`1521`	`1521`	`snapshot->xcnt * sizeof(TransactionId);`