From c029a6a49e3782ec5f1a61eb9a495ebd2a56077d Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 31 Mar 2009 22:54:31 +0000
Subject: [PATCH] Fix contrib/pgstattuple and contrib/pageinspect to prevent
attempts to read temporary tables of other sessions; that is unsafe because
of the way our buffer management works. Per report from Stuart Bishop. This
is redundant with the bufmgr.c checks in HEAD, but not at all redundant in
the back branches.
---
contrib/pageinspect/btreefuncs.c | 32 ++++++++++++++++++++++++++++++-
contrib/pageinspect/rawpage.c | 12 +++++++++++-
contrib/pgstattuple/pgstatindex.c | 14 +++++++++++++-
contrib/pgstattuple/pgstattuple.c | 12 +++++++++++-
4 files changed, 66 insertions(+), 4 deletions(-)
diff --git a/contrib/pageinspect/btreefuncs.c b/contrib/pageinspect/btreefuncs.c
index ab80b545000..85935b99905 100644
--- a/contrib/pageinspect/btreefuncs.c
+++ b/contrib/pageinspect/btreefuncs.c
@@ -1,5 +1,5 @@
/*
- * $PostgreSQL: pgsql/contrib/pageinspect/btreefuncs.c,v 1.8 2008/05/17 01:28:19 adunstan Exp $
+ * $PostgreSQL: pgsql/contrib/pageinspect/btreefuncs.c,v 1.9 2009/03/31 22:54:31 tgl Exp $
*
*
* btreefuncs.c
@@ -190,6 +190,16 @@ bt_page_stats(PG_FUNCTION_ARGS)
elog(ERROR, "relation \"%s\" is not a btree index",
RelationGetRelationName(rel));
+ /*
+ * Reject attempts to read non-local temporary relations; we would
+ * be likely to get wrong data since we have no visibility into the
+ * owning session's local buffers.
+ */
+ if (RELATION_IS_OTHER_TEMP(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot access temporary tables of other sessions")));
+
if (blkno == 0)
elog(ERROR, "block 0 is a meta page");
@@ -298,6 +308,16 @@ bt_page_items(PG_FUNCTION_ARGS)
elog(ERROR, "relation \"%s\" is not a btree index",
RelationGetRelationName(rel));
+ /*
+ * Reject attempts to read non-local temporary relations; we would
+ * be likely to get wrong data since we have no visibility into the
+ * owning session's local buffers.
+ */
+ if (RELATION_IS_OTHER_TEMP(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot access temporary tables of other sessions")));
+
if (blkno == 0)
elog(ERROR, "block 0 is a meta page");
@@ -437,6 +457,16 @@ bt_metap(PG_FUNCTION_ARGS)
elog(ERROR, "relation \"%s\" is not a btree index",
RelationGetRelationName(rel));
+ /*
+ * Reject attempts to read non-local temporary relations; we would
+ * be likely to get wrong data since we have no visibility into the
+ * owning session's local buffers.
+ */
+ if (RELATION_IS_OTHER_TEMP(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot access temporary tables of other sessions")));
+
buffer = ReadBuffer(rel, 0);
page = BufferGetPage(buffer);
metad = BTPageGetMeta(page);
diff --git a/contrib/pageinspect/rawpage.c b/contrib/pageinspect/rawpage.c
index 607f55eef0a..91b6a1915f0 100644
--- a/contrib/pageinspect/rawpage.c
+++ b/contrib/pageinspect/rawpage.c
@@ -8,7 +8,7 @@
* Copyright (c) 2007-2009, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/contrib/pageinspect/rawpage.c,v 1.10 2009/01/01 17:23:32 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/pageinspect/rawpage.c,v 1.11 2009/03/31 22:54:31 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -74,6 +74,16 @@ get_raw_page(PG_FUNCTION_ARGS)
errmsg("cannot get raw page from composite type \"%s\"",
RelationGetRelationName(rel))));
+ /*
+ * Reject attempts to read non-local temporary relations; we would
+ * be likely to get wrong data since we have no visibility into the
+ * owning session's local buffers.
+ */
+ if (RELATION_IS_OTHER_TEMP(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot access temporary tables of other sessions")));
+
if (blkno >= RelationGetNumberOfBlocks(rel))
elog(ERROR, "block number %u is out of range for relation \"%s\"",
blkno, RelationGetRelationName(rel));
diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c
index dfb162d5e45..b00ae5b766b 100644
--- a/contrib/pgstattuple/pgstatindex.c
+++ b/contrib/pgstattuple/pgstatindex.c
@@ -1,5 +1,5 @@
/*
- * $PostgreSQL: pgsql/contrib/pgstattuple/pgstatindex.c,v 1.11 2008/05/17 01:28:22 adunstan Exp $
+ * $PostgreSQL: pgsql/contrib/pgstattuple/pgstatindex.c,v 1.12 2009/03/31 22:54:31 tgl Exp $
*
*
* pgstatindex
@@ -107,6 +107,16 @@ pgstatindex(PG_FUNCTION_ARGS)
elog(ERROR, "relation \"%s\" is not a btree index",
RelationGetRelationName(rel));
+ /*
+ * Reject attempts to read non-local temporary relations; we would
+ * be likely to get wrong data since we have no visibility into the
+ * owning session's local buffers.
+ */
+ if (RELATION_IS_OTHER_TEMP(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot access temporary tables of other sessions")));
+
/*
* Read metapage
*/
@@ -262,6 +272,8 @@ pg_relpages(PG_FUNCTION_ARGS)
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
+ /* note: this will work OK on non-local temp tables */
+
relpages = RelationGetNumberOfBlocks(rel);
relation_close(rel, AccessShareLock);
diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
index f4c046ca8c5..c2c5d11e5a6 100644
--- a/contrib/pgstattuple/pgstattuple.c
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -1,5 +1,5 @@
/*
- * $PostgreSQL: pgsql/contrib/pgstattuple/pgstattuple.c,v 1.36 2008/06/19 00:46:03 alvherre Exp $
+ * $PostgreSQL: pgsql/contrib/pgstattuple/pgstattuple.c,v 1.37 2009/03/31 22:54:31 tgl Exp $
*
* Copyright (c) 2001,2002 Tatsuo Ishii
*
@@ -199,6 +199,16 @@ pgstat_relation(Relation rel, FunctionCallInfo fcinfo)
{
const char *err;
+ /*
+ * Reject attempts to read non-local temporary relations; we would
+ * be likely to get wrong data since we have no visibility into the
+ * owning session's local buffers.
+ */
+ if (RELATION_IS_OTHER_TEMP(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot access temporary tables of other sessions")));
+
switch (rel->rd_rel->relkind)
{
case RELKIND_RELATION:
--
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