From fa2642438f189c2b169ace3ac1df19533b9c7781 Mon Sep 17 00:00:00 2001
From: Stephen Frost <sfrost@snowman.net>
Date: Mon, 11 May 2015 15:44:12 -0400
Subject: [PATCH] Allow LOCK TABLE .. ROW EXCLUSIVE MODE with INSERT
INSERT acquires RowExclusiveLock during normal operation and therefore
it makes sense to allow LOCK TABLE .. ROW EXCLUSIVE MODE to be executed
by users who have INSERT rights on a table (even if they don't have
UPDATE or DELETE).
Not back-patching this as it's a behavior change which, strictly
speaking, loosens security restrictions.
Per discussion with Tom and Robert (circa 2013).
---
doc/src/sgml/ref/lock.sgml | 8 +++++---
src/backend/commands/lockcmds.c | 12 ++++++++----
2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/ref/lock.sgml b/doc/src/sgml/ref/lock.sgml
index 913afe76dd4..b946eab3039 100644
--- a/doc/src/sgml/ref/lock.sgml
+++ b/doc/src/sgml/ref/lock.sgml
@@ -161,9 +161,11 @@ LOCK [ TABLE ] [ ONLY ] <replaceable class="PARAMETER">name</replaceable> [ * ]
<para>
<literal>LOCK TABLE ... IN ACCESS SHARE MODE</> requires <literal>SELECT</>
- privileges on the target table. All other forms of <command>LOCK</>
- require table-level <literal>UPDATE</>, <literal>DELETE</>, or
- <literal>TRUNCATE</> privileges.
+ privileges on the target table. <literal>LOCK TABLE ... IN ROW EXCLUSIVE
+ MODE</> requires <literal>INSERT</>, <literal>UPDATE</>, <literal>DELETE</>,
+ or <literal>TRUNCATE</> privileges on the target table. All other forms of
+ <command>LOCK</> require table-level <literal>UPDATE</>, <literal>DELETE</>,
+ or <literal>TRUNCATE</> privileges.
</para>
<para>
diff --git a/src/backend/commands/lockcmds.c b/src/backend/commands/lockcmds.c
index bdec2ff545c..a1670821aa4 100644
--- a/src/backend/commands/lockcmds.c
+++ b/src/backend/commands/lockcmds.c
@@ -169,13 +169,17 @@ static AclResult
LockTableAclCheck(Oid reloid, LOCKMODE lockmode)
{
AclResult aclresult;
+ AclMode aclmask;
/* Verify adequate privilege */
if (lockmode == AccessShareLock)
- aclresult = pg_class_aclcheck(reloid, GetUserId(),
- ACL_SELECT);
+ aclmask = ACL_SELECT;
+ else if (lockmode == RowExclusiveLock)
+ aclmask = ACL_INSERT | ACL_UPDATE | ACL_DELETE | ACL_TRUNCATE;
else
- aclresult = pg_class_aclcheck(reloid, GetUserId(),
- ACL_UPDATE | ACL_DELETE | ACL_TRUNCATE);
+ aclmask = ACL_UPDATE | ACL_DELETE | ACL_TRUNCATE;
+
+ aclresult = pg_class_aclcheck(reloid, GetUserId(), aclmask);
+
return aclresult;
}
--
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