postgres.git / summary / log / commit / refs

commit    317be817f4287168a8722377bcd4e26cef817c28
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Mon Jan 18 02:30:37 2010 +0000
First released in: 9.0.0, 8.3.10, 8.4.3

    Fix portalmem.c to avoid keeping a dangling pointer to a cached plan list
    after it's released its reference count for the cached plan.  There are
    code paths that might try to examine the plan list before noticing that
    the portal is already in aborted state.  Report and diagnosis by Tatsuo
    Ishii, though this isn't exactly his proposed patch.


 src/backend/utils/mmgr/portalmem.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index 217c6b1234b..7fe28ca15fa 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.106.2.2 2009/12/29 17:41:18 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.106.2.3 2010/01/18 02:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -324,6 +324,13 @@ PortalReleaseCachedPlan(Portal portal)
 	{
 		ReleaseCachedPlan(portal->cplan, false);
 		portal->cplan = NULL;
+
+		/*
+		 * We must also clear portal->stmts which is now a dangling
+		 * reference to the cached plan's plan list.  This protects any
+		 * code that might try to examine the Portal later.
+		 */
+		portal->stmts = NIL;
 	}
 }
 
@@ -385,8 +392,7 @@ PortalDrop(Portal portal, bool isTopCommit)
 		(*portal->cleanup) (portal);
 
 	/* drop cached plan reference, if any */
-	if (portal->cplan)
-		PortalReleaseCachedPlan(portal);
+	PortalReleaseCachedPlan(portal);
 
 	/*
 	 * Release any resources still attached to the portal.	There are several
@@ -519,8 +525,7 @@ CommitHoldablePortals(void)
 			PersistHoldablePortal(portal);
 
 			/* drop cached plan reference, if any */
-			if (portal->cplan)
-				PortalReleaseCachedPlan(portal);
+			PortalReleaseCachedPlan(portal);
 
 			/*
 			 * Any resources belonging to the portal will be released in the
@@ -670,8 +675,7 @@ AtAbort_Portals(void)
 		}
 
 		/* drop cached plan reference, if any */
-		if (portal->cplan)
-			PortalReleaseCachedPlan(portal);
+		PortalReleaseCachedPlan(portal);
 
 		/*
 		 * Any resources belonging to the portal will be released in the
@@ -813,8 +817,7 @@ AtSubAbort_Portals(SubTransactionId mySubid,
 			}
 
 			/* drop cached plan reference, if any */
-			if (portal->cplan)
-				PortalReleaseCachedPlan(portal);
+			PortalReleaseCachedPlan(portal);
 
 			/*
 			 * Any resources belonging to the portal will be released in the


[parent: 8a6a40dea66e]