From 9a6e3dfb23da8f4801d36e0285f11e593abf1b7a Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 31 Mar 2009 22:54:52 +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 | 30 ++++++++++++++++++++++++++++++ contrib/pageinspect/rawpage.c | 10 ++++++++++ contrib/pgstattuple/pgstatindex.c | 12 ++++++++++++ contrib/pgstattuple/pgstattuple.c | 10 ++++++++++ 4 files changed, 62 insertions(+) diff --git a/contrib/pageinspect/btreefuncs.c b/contrib/pageinspect/btreefuncs.c index ce8b97e46b..c50c5da0bd 100644 --- a/contrib/pageinspect/btreefuncs.c +++ b/contrib/pageinspect/btreefuncs.c @@ -186,6 +186,16 @@ 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 (isOtherTempNamespace(RelationGetNamespace(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"); @@ -294,6 +304,16 @@ 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 (isOtherTempNamespace(RelationGetNamespace(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"); @@ -433,6 +453,16 @@ 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 (isOtherTempNamespace(RelationGetNamespace(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 508ffe801e..43c20249c1 100644 --- a/contrib/pageinspect/rawpage.c +++ b/contrib/pageinspect/rawpage.c @@ -68,6 +68,16 @@ 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 (isOtherTempNamespace(RelationGetNamespace(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 3cd3147895..f766739d74 100644 --- a/contrib/pgstattuple/pgstatindex.c +++ b/contrib/pgstattuple/pgstatindex.c @@ -103,6 +103,16 @@ 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 (isOtherTempNamespace(RelationGetNamespace(rel))) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot access temporary tables of other sessions"))); + /* * Read metapage */ @@ -261,6 +271,8 @@ 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 0f9de66344..2e64534e5c 100644 --- a/contrib/pgstattuple/pgstattuple.c +++ b/contrib/pgstattuple/pgstattuple.c @@ -196,6 +196,16 @@ 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 (isOtherTempNamespace(RelationGetNamespace(rel))) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot access temporary tables of other sessions"))); + switch (rel->rd_rel->relkind) { case RELKIND_RELATION: -- 2.39.5