* Dean Rasheed (dean.a.rash...@gmail.com) wrote: > On 27 August 2015 at 13:49, Andres Freund <and...@anarazel.de> wrote: > > The locking around rowsecurity policy expressions seems to be > > insufficient: > > SELECT * FROM document WHERE f_leak(dtitle) ORDER BY did; > > WARNING: RelationIdGetRelation(247984) without holding lock on the relation > > WARNING: relation_open(247984, NoLock) of relation "uaccount" without > > previously held lock [...] > > Istmt that something like > > context.for_execute = true; > > acquireLocksOnSubLinks((Node *) > > securityQuals, &context); > > acquireLocksOnSubLinks((Node *) > > withCheckOptions, &context); > > needs to be added to that code. > > Yes, I think you're right. It needs to happen before fireRIRonSubLink, > and only if hasSubLinks is true.
Attached appears to fix this for the RLS case from my testing.
Any comments?
Barring concerns, I'll push this later today and back-patch to 9.5.
Thanks!
Stephen
From 7ac58a62338103338b6907fc7ea89f9afb9a0e53 Mon Sep 17 00:00:00 2001
From: Stephen Frost <sfr...@snowman.net>
Date: Fri, 28 Aug 2015 08:10:22 -0400
Subject: [PATCH] Ensure locks are acquired on RLS-added relations
During fireRIRrules(), get_row_security_policies can add to
securityQuals and withCheckOptions. Make sure to lock any relations
added at that point and before firing RIR rules on those expressions.
Back-patch to 9.5 where RLS was added.
---
src/backend/rewrite/rewriteHandler.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 1734e48..fbc0c57 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -1787,6 +1787,8 @@ fireRIRrules(Query *parsetree, List *activeRIRs, bool forUpdatePushedDown)
{
if (hasSubLinks)
{
+ acquireLocksOnSubLinks_context context;
+
/*
* Recursively process the new quals, checking for infinite
* recursion.
@@ -1799,6 +1801,20 @@ fireRIRrules(Query *parsetree, List *activeRIRs, bool forUpdatePushedDown)
activeRIRs = lcons_oid(RelationGetRelid(rel), activeRIRs);
+ /*
+ * get_row_security_policies just added to securityQuals and/or
+ * withCheckOptions, and there were SubLinks, so make sure
+ * we lock any relations which were added as a result.
+ */
+ context.for_execute = true;
+ (void) acquireLocksOnSubLinks((Node *) securityQuals, &context);
+ (void) acquireLocksOnSubLinks((Node *) withCheckOptions,
+ &context);
+
+ /*
+ * Now that we have the locks on anything added by
+ * get_row_security_policies, fire any RIR rules for them.
+ */
expression_tree_walker((Node *) securityQuals,
fireRIRonSubLink, (void *) activeRIRs);
--
1.9.1
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