mirror of
https://github.com/postgres/postgres.git
synced 2026-03-10 10:11:28 -04:00
688dc6299a
Presently, these functions look up the relation's OID, lock it, and then check privileges. Not only does this approach provide no guarantee that the locked relation matches the arguments of the lookup, but it also allows users to briefly lock relations for which they do not have privileges, which might enable denial-of-service attacks. This commit adjusts these functions to use RangeVarGetRelidExtended(), which is purpose-built to avoid both of these issues. The new RangeVarGetRelidCallback function is somewhat complicated because it must handle both tables and indexes, and for indexes, we must check privileges on the parent table and lock it first. Also, it needs to handle a couple of extremely unlikely race conditions involving concurrent OID reuse. A downside of this change is that the coding doesn't allow for locking indexes in AccessShare mode anymore; everything is locked in ShareUpdateExclusive mode. Per discussion, the original choice of lock levels was intended for a now defunct implementation that used in-place updates, so we believe this change is okay. Reviewed-by: Jeff Davis <pgsql@j-davis.com> Discussion: https://postgr.es/m/Z8zwVmGzXyDdkAXj%40nathan Backpatch-through: 18
43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* stat_utils.h
|
|
* Extended statistics and selectivity estimation functions.
|
|
*
|
|
* Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
* src/include/statistics/stat_utils.h
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#ifndef STATS_UTILS_H
|
|
#define STATS_UTILS_H
|
|
|
|
#include "fmgr.h"
|
|
|
|
/* avoid including primnodes.h here */
|
|
typedef struct RangeVar RangeVar;
|
|
|
|
struct StatsArgInfo
|
|
{
|
|
const char *argname;
|
|
Oid argtype;
|
|
};
|
|
|
|
extern void stats_check_required_arg(FunctionCallInfo fcinfo,
|
|
struct StatsArgInfo *arginfo,
|
|
int argnum);
|
|
extern bool stats_check_arg_array(FunctionCallInfo fcinfo,
|
|
struct StatsArgInfo *arginfo, int argnum);
|
|
extern bool stats_check_arg_pair(FunctionCallInfo fcinfo,
|
|
struct StatsArgInfo *arginfo,
|
|
int argnum1, int argnum2);
|
|
|
|
extern void RangeVarCallbackForStats(const RangeVar *relation,
|
|
Oid relId, Oid oldRelid, void *arg);
|
|
|
|
extern bool stats_fill_fcinfo_from_arg_pairs(FunctionCallInfo pairs_fcinfo,
|
|
FunctionCallInfo positional_fcinfo,
|
|
struct StatsArgInfo *arginfo);
|
|
|
|
#endif /* STATS_UTILS_H */
|