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Fix superuser concurrent refresh of matview owned by another.

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Use SECURITY_LOCAL_USERID_CHANGE while building temporary tables;
only escalate to SECURITY_RESTRICTED_OPERATION while potentially
running user-supplied code.  The more secure mode was preventing
temp table creation.  Add regression tests to cover this problem.

This fixes Bug #11208 reported by Bruno Emanuel de Andrade Silva.

Backpatch to 9.4, where the bug was introduced.
This commit is contained in:
Kevin Grittner
2014-08-26 09:56:26 -05:00
parent 5569d75d6a
commit a9d0f1cff3
3 changed files with 70 additions and 48 deletions
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93
src/backend/commands/matview.c
View File

@ -59,12 +59,13 @@ static void transientrel_receive(TupleTableSlot *slot, DestReceiver *self);
static void transientrel_shutdown(DestReceiver *self);
static void transientrel_destroy(DestReceiver *self);
static void refresh_matview_datafill(DestReceiver *dest, Query *query,
const char *queryString, Oid relowner);
const char *queryString);
static char *make_temptable_name_n(char *tempname, int n);
static void mv_GenerateOper(StringInfo buf, Oid opoid);
static void refresh_by_match_merge(Oid matviewOid, Oid tempOid);
static void refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner,
int save_sec_context);
static void refresh_by_heap_swap(Oid matviewOid, Oid OIDNewHeap);
static void OpenMatViewIncrementalMaintenance(void);
@ -142,12 +143,15 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
List *actions;
Query *dataQuery;
Oid tableSpace;
Oid owner;
Oid relowner;
Oid OIDNewHeap;
DestReceiver *dest;
bool concurrent;
LOCKMODE lockmode;
char relpersistence;
Oid save_userid;
int save_sec_context;
int save_nestlevel;
/* Determine strength of lock needed. */
concurrent = stmt->concurrent;
@ -232,6 +236,19 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
*/
SetMatViewPopulatedState(matviewRel, !stmt->skipData);
relowner = matviewRel->rd_rel->relowner;
/*
* Switch to the owner's userid, so that any functions are run as that
* user. Also arrange to make GUC variable changes local to this command.
* Don't lock it down too tight to create a temporary table just yet. We
* will switch modes when we are about to execute user code.
*/
GetUserIdAndSecContext(&save_userid, &save_sec_context);
SetUserIdAndSecContext(relowner,
save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
save_nestlevel = NewGUCNestLevel();
/* Concurrent refresh builds new data in temp tablespace, and does diff. */
if (concurrent)
{
@ -244,8 +261,6 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
relpersistence = matviewRel->rd_rel->relpersistence;
}
owner = matviewRel->rd_rel->relowner;
/*
* Create the transient table that will receive the regenerated data. Lock
* it against access by any other process until commit (by which time it
@ -256,9 +271,15 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
LockRelationOid(OIDNewHeap, AccessExclusiveLock);
dest = CreateTransientRelDestReceiver(OIDNewHeap);
/*
* Now lock down security-restricted operations.
*/
SetUserIdAndSecContext(relowner,
save_sec_context | SECURITY_RESTRICTED_OPERATION);
/* Generate the data, if wanted. */
if (!stmt->skipData)
refresh_matview_datafill(dest, dataQuery, queryString, owner);
refresh_matview_datafill(dest, dataQuery, queryString);
heap_close(matviewRel, NoLock);
@ -269,7 +290,8 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
PG_TRY();
{
refresh_by_match_merge(matviewOid, OIDNewHeap);
refresh_by_match_merge(matviewOid, OIDNewHeap, relowner,
save_sec_context);
}
PG_CATCH();
{
@ -282,6 +304,12 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
else
refresh_by_heap_swap(matviewOid, OIDNewHeap);
/* Roll back any GUC changes */
AtEOXact_GUC(false, save_nestlevel);
/* Restore userid and security context */
SetUserIdAndSecContext(save_userid, save_sec_context);
return matviewOid;
}
@ -290,26 +318,13 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
*/
static void
refresh_matview_datafill(DestReceiver *dest, Query *query,
const char *queryString, Oid relowner)
const char *queryString)
{
List *rewritten;
PlannedStmt *plan;
QueryDesc *queryDesc;
Oid save_userid;
int save_sec_context;
int save_nestlevel;
Query *copied_query;
/*
* Switch to the owner's userid, so that any functions are run as that
* user. Also lock down security-restricted operations and arrange to
* make GUC variable changes local to this command.
*/
GetUserIdAndSecContext(&save_userid, &save_sec_context);
SetUserIdAndSecContext(relowner,
save_sec_context | SECURITY_RESTRICTED_OPERATION);
save_nestlevel = NewGUCNestLevel();
/* Lock and rewrite, using a copy to preserve the original query. */
copied_query = copyObject(query);
AcquireRewriteLocks(copied_query, true, false);
@ -353,12 +368,6 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
FreeQueryDesc(queryDesc);
PopActiveSnapshot();
/* Roll back any GUC changes */
AtEOXact_GUC(false, save_nestlevel);
/* Restore userid and security context */
SetUserIdAndSecContext(save_userid, save_sec_context);
}
DestReceiver *
@ -529,7 +538,8 @@ mv_GenerateOper(StringInfo buf, Oid opoid)
* this command.
*/
static void
refresh_by_match_merge(Oid matviewOid, Oid tempOid)
refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner,
int save_sec_context)
{
StringInfoData querybuf;
Relation matviewRel;
@ -543,9 +553,6 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid)
ListCell *indexoidscan;
int16 relnatts;
bool *usedForQual;
Oid save_userid;
int save_sec_context;
int save_nestlevel;
initStringInfo(&querybuf);
matviewRel = heap_open(matviewOid, NoLock);
@ -596,6 +603,9 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid)
SPI_getvalue(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1))));
}
SetUserIdAndSecContext(relowner,
save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
/* Start building the query for creating the diff table. */
resetStringInfo(&querybuf);
appendStringInfo(&querybuf,
@ -690,9 +700,12 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid)
if (SPI_exec(querybuf.data, 0) != SPI_OK_UTILITY)
elog(ERROR, "SPI_exec failed: %s", querybuf.data);
SetUserIdAndSecContext(relowner,
save_sec_context | SECURITY_RESTRICTED_OPERATION);
/*
* We have no further use for data from the "full-data" temp table, but we
* must keep it around because its type is reference from the diff table.
* must keep it around because its type is referenced from the diff table.
*/
/* Analyze the diff table. */
@ -703,16 +716,6 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid)
OpenMatViewIncrementalMaintenance();
/*
* Switch to the owner's userid, so that any functions are run as that
* user. Also lock down security-restricted operations and arrange to
* make GUC variable changes local to this command.
*/
GetUserIdAndSecContext(&save_userid, &save_sec_context);
SetUserIdAndSecContext(matviewRel->rd_rel->relowner,
save_sec_context | SECURITY_RESTRICTED_OPERATION);
save_nestlevel = NewGUCNestLevel();
/* Deletes must come before inserts; do them first. */
resetStringInfo(&querybuf);
appendStringInfo(&querybuf,
@ -733,12 +736,6 @@ refresh_by_match_merge(Oid matviewOid, Oid tempOid)
if (SPI_exec(querybuf.data, 0) != SPI_OK_INSERT)
elog(ERROR, "SPI_exec failed: %s", querybuf.data);
/* Roll back any GUC changes */
AtEOXact_GUC(false, save_nestlevel);
/* Restore userid and security context */
SetUserIdAndSecContext(save_userid, save_sec_context);
/* We're done maintaining the materialized view. */
CloseMatViewIncrementalMaintenance();
heap_close(tempRel, NoLock);