Fix dangling pointer access

knizhnik · knizhnik · commit 2edd41b0c58d · 2017-02-14T18:08:44.000+03:00
diff --git a/contrib/mmts/pglogical_apply.c b/contrib/mmts/pglogical_apply.c
@@ -662,7 +662,7 @@ process_remote_commit(StringInfo in)
 		case PGLOGICAL_PREPARE:
 		{
 			Assert(IsTransactionState() && TransactionIdIsValid(MtmGetCurrentTransactionId()));
-			gid = pq_getmsgstring(in);
+			gid = pstrdup(pq_getmsgstring(in)); /* in case of spilling large transaction to the file, message body will be deallocated, so copy it */
 			if (MtmExchangeGlobalTransactionStatus(gid, TRANSACTION_STATUS_IN_PROGRESS) == TRANSACTION_STATUS_ABORTED) { 
 				MTM_LOG1("Avoid prepare of previously aborted global transaction %s", gid);	
 				AbortCurrentTransaction();

Original file line number	Diff line number	Diff line change
`@@ -662,7 +662,7 @@ process_remote_commit(StringInfo in)`
`662`	`662`	`case PGLOGICAL_PREPARE:`
`663`	`663`	`{`
`664`	`664`	`Assert(IsTransactionState() && TransactionIdIsValid(MtmGetCurrentTransactionId()));`
`665`		`- gid = pq_getmsgstring(in);`
	`665`	`+ gid = pstrdup(pq_getmsgstring(in)); /* in case of spilling large transaction to the file, message body will be deallocated, so copy it */`
`666`	`666`	`if (MtmExchangeGlobalTransactionStatus(gid, TRANSACTION_STATUS_IN_PROGRESS) == TRANSACTION_STATUS_ABORTED) {`
`667`	`667`	`MTM_LOG1("Avoid prepare of previously aborted global transaction %s", gid);`
`668`	`668`	`AbortCurrentTransaction();`