From 524d357d09cd42a1e88636f2bc6a66bc402ca0a1 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 18 Jan 2010 02:30:30 +0000 Subject: [PATCH] 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 a8ee35f08a7..501ffb1635c 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 1.113.2.1 2009/12/29 17:41:09 heikki Exp $ + * $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.113.2.2 2010/01/18 02:30:30 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -328,6 +328,13 @@ 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; } } @@ -395,8 +402,7 @@ 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 @@ -529,8 +535,7 @@ 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 @@ -680,8 +685,7 @@ 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 @@ -823,8 +827,7 @@ 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