From 9564e6584a19fdd245558e96e8c15c40101046ea Mon Sep 17 00:00:00 2001 From: Antonin Houska Date: Wed, 16 Sep 2026 18:47:27 +0200 Subject: [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Whenever we expect possible execution of index functions, we need to make sure that they execute with the appropriate privileges. Also, the core should not see (and use) values of GUC parameters introduced by the index functions. This patch introduces functions enable_index_build_security() and disable_index_build_security() which make the security measures less verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY), but looks like useful refactoring anyway. --- src/backend/access/brin/brin.c | 32 +++-------- src/backend/access/heap/heapam_handler.c | 1 + src/backend/catalog/index.c | 72 +++++++++++++----------- src/backend/commands/analyze.c | 21 ++----- src/backend/commands/indexcmds.c | 49 +++++----------- src/backend/commands/repack.c | 32 ++++------- src/backend/commands/vacuum.c | 23 ++------ src/include/catalog/index.h | 10 ++++ src/tools/pgindent/typedefs.list | 1 + 9 files changed, 95 insertions(+), 146 deletions(-) diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c index 5059da8dce7..cfac3b80f27 100644 --- a/src/backend/access/brin/brin.c +++ b/src/backend/access/brin/brin.c @@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS) Oid heapoid; Relation indexRel; Relation heapRel; - Oid save_userid; - int save_sec_context; - int save_nestlevel; double numSummarized = 0; + IndexBuildSecurity ibsec; if (RecoveryInProgress()) ereport(ERROR, @@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS) heapRel = table_open(heapoid, ShareUpdateExclusiveLock); /* - * Autovacuum calls us. For its benefit, switch to the table owner's - * userid, so that any index functions are run as that user. Also - * lock down security-restricted operations and arrange to make GUC - * variable changes local to this command. This is harmless, albeit - * unnecessary, when called from SQL, because we fail shortly if the - * user does not own the index. + * Prevent index functions from doing what they are not supposed to. */ - GetUserIdAndSecContext(&save_userid, &save_sec_context); - SetUserIdAndSecContext(heapRel->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(heapRel->rd_rel->relowner, &ibsec); } else - { heapRel = NULL; - /* Set these just to suppress "uninitialized variable" warnings */ - save_userid = InvalidOid; - save_sec_context = -1; - save_nestlevel = -1; - } indexRel = index_open(indexoid, ShareUpdateExclusiveLock); @@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS) RelationGetRelationName(indexRel)))); /* User must own the index (comparable to privileges needed for VACUUM) */ - if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid)) + if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, + ibsec.userid)) aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX, RelationGetRelationName(indexRel)); @@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS) errmsg("index \"%s\" is not valid", RelationGetRelationName(indexRel)))); - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); index_close(indexRel, ShareUpdateExclusiveLock); table_close(heapRel, ShareUpdateExclusiveLock); diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c index d0a9c757158..2400206414a 100644 --- a/src/backend/access/heap/heapam_handler.c +++ b/src/backend/access/heap/heapam_handler.c @@ -764,6 +764,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap, */ pgstat_progress_update_param(PROGRESS_REPACK_HEAP_BLKS_SCANNED, heapScan->rs_nblocks); + break; } diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index ec21b83b6b8..94f0c4080c0 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -1519,11 +1519,9 @@ index_concurrently_build(Oid heapRelationId, Oid indexRelationId) { Relation heapRel; - Oid save_userid; - int save_sec_context; - int save_nestlevel; Relation indexRelation; IndexInfo *indexInfo; + IndexBuildSecurity ibsec; /* This had better make sure that a snapshot is active */ Assert(ActiveSnapshotSet()); @@ -1532,15 +1530,9 @@ index_concurrently_build(Oid heapRelationId, heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock); /* - * Switch to the table owner's userid, so that any index functions are run - * as that user. Also lock down security-restricted operations and - * arrange to make GUC variable changes local to this command. + * Prevent index functions from doing what they are not supposed to. */ - GetUserIdAndSecContext(&save_userid, &save_sec_context); - SetUserIdAndSecContext(heapRel->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(heapRel->rd_rel->relowner, &ibsec); indexRelation = index_open(indexRelationId, RowExclusiveLock); @@ -1557,11 +1549,8 @@ index_concurrently_build(Oid heapRelationId, /* Now build the index */ index_build(heapRel, indexRelation, indexInfo, false, true, true); - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); - - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); /* Close both the relations, but keep the locks */ table_close(heapRel, NoLock); @@ -3403,9 +3392,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot) IndexInfo *indexInfo; IndexVacuumInfo ivinfo; ValidateIndexState state; - Oid save_userid; - int save_sec_context; - int save_nestlevel; + IndexBuildSecurity ibsec; { const int progress_index[] = { @@ -3427,15 +3414,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot) heapRelation = table_open(heapId, ShareUpdateExclusiveLock); /* - * Switch to the table owner's userid, so that any index functions are run - * as that user. Also lock down security-restricted operations and - * arrange to make GUC variable changes local to this command. + * Prevent index functions from doing what they are not supposed to. */ - GetUserIdAndSecContext(&save_userid, &save_sec_context); - SetUserIdAndSecContext(heapRelation->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec); indexRelation = index_open(indexId, RowExclusiveLock); @@ -3514,11 +3495,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot) "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples", state.htups, state.itups, state.tups_inserted); - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); - - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); /* Close rels, but keep locks */ index_close(indexRelation, NoLock); @@ -4143,6 +4121,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags, return result; } +/* + * Before building an index, witch to the table owner's userid, so that any + * index functions are run as that user. Also lock down security-restricted + * operations and arrange to make GUC variable changes local to this command. + * + * Information needed later by disable_index_build_security() is stored in + * *sec. + */ +void +enable_index_build_security(Oid userid, IndexBuildSecurity *sec) +{ + GetUserIdAndSecContext(&sec->userid, &sec->sec_context); + SetUserIdAndSecContext(userid, + sec->sec_context | SECURITY_RESTRICTED_OPERATION); + sec->nestlevel = NewGUCNestLevel(); + RestrictSearchPath(); +} + +/* + * Undo what enable_index_build_security() did. + */ +void +disable_index_build_security(IndexBuildSecurity *sec) +{ + /* Roll back any GUC changes executed by index functions */ + AtEOXact_GUC(false, sec->nestlevel); + + /* Restore userid and security context */ + SetUserIdAndSecContext(sec->userid, sec->sec_context); +} /* ---------------------------------------------------------------- * System index reindexing support diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index c05f9f50e43..c9312eca218 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -329,14 +329,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params, PGRUsage ru0; TimestampTz starttime = 0; MemoryContext caller_context; - Oid save_userid; - int save_sec_context; - int save_nestlevel; WalUsage startwalusage = pgWalUsage; BufferUsage startbufferusage = pgBufferUsage; BufferUsage bufferusage; PgStat_Counter startreadtime = 0; PgStat_Counter startwritetime = 0; + IndexBuildSecurity ibsec; verbose = (params->options & VACOPT_VERBOSE) != 0; instrument = (verbose || (AmAutoVacuumWorkerProcess() && @@ -362,15 +360,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params, caller_context = MemoryContextSwitchTo(anl_context); /* - * Switch to the table owner's userid, so that any index functions are run - * as that user. Also lock down security-restricted operations and - * arrange to make GUC variable changes local to this command. + * Prevent index functions from doing what they are not supposed to. */ - GetUserIdAndSecContext(&save_userid, &save_sec_context); - SetUserIdAndSecContext(onerel->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(onerel->rd_rel->relowner, &ibsec); /* * When verbose or autovacuum logging is used, initialize a resource usage @@ -857,11 +849,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params, } } - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); - - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); /* Restore current context and release memory */ MemoryContextSwitchTo(caller_context); diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c index 5a0312fe772..7ff5780ffbc 100644 --- a/src/backend/commands/indexcmds.c +++ b/src/backend/commands/indexcmds.c @@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate, * Switch to the table owner's userid, so that any index functions are run * as that user. Also lock down security-restricted operations. We * already arranged to make GUC variable changes local to this command. + * + * XXX Use enable_index_build_security()? */ GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context); SetUserIdAndSecContext(rel->rd_rel->relowner, @@ -1402,22 +1404,16 @@ DefineIndex(ParseState *pstate, { Oid childRelid = part_oids[i]; Relation childrel; - Oid child_save_userid; - int child_save_sec_context; - int child_save_nestlevel; List *childidxs; ListCell *cell; AttrMap *attmap; bool found = false; + IndexBuildSecurity child_ibsec; childrel = table_open(childRelid, lockmode); - GetUserIdAndSecContext(&child_save_userid, - &child_save_sec_context); - SetUserIdAndSecContext(childrel->rd_rel->relowner, - child_save_sec_context | SECURITY_RESTRICTED_OPERATION); - child_save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(childrel->rd_rel->relowner, + &child_ibsec); /* * Don't try to create indexes on foreign tables, though. Skip @@ -1434,9 +1430,7 @@ DefineIndex(ParseState *pstate, errdetail("Table \"%s\" contains partitions that are foreign tables.", RelationGetRelationName(rel)))); - AtEOXact_GUC(false, child_save_nestlevel); - SetUserIdAndSecContext(child_save_userid, - child_save_sec_context); + disable_index_build_security(&child_ibsec); table_close(childrel, lockmode); continue; } @@ -1521,9 +1515,7 @@ DefineIndex(ParseState *pstate, } list_free(childidxs); - AtEOXact_GUC(false, child_save_nestlevel); - SetUserIdAndSecContext(child_save_userid, - child_save_sec_context); + disable_index_build_security(&child_ibsec); table_close(childrel, NoLock); /* @@ -1550,7 +1542,7 @@ DefineIndex(ParseState *pstate, * Recurse as the starting user ID. Callee will use that * for permission checks, then switch again. */ - Assert(GetUserId() == child_save_userid); + Assert(GetUserId() == child_ibsec.userid); SetUserIdAndSecContext(root_save_userid, root_save_sec_context); childAddr = @@ -1563,8 +1555,8 @@ DefineIndex(ParseState *pstate, is_alter_table, check_rights, check_not_in_use, skip_build, quiet); - SetUserIdAndSecContext(child_save_userid, - child_save_sec_context); + SetUserIdAndSecContext(child_ibsec.userid, + child_ibsec.sec_context); /* * Check if the index just created is valid or not, as it @@ -4080,27 +4072,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein Oid newIndexId; Relation indexRel; Relation heapRel; - Oid save_userid; - int save_sec_context; - int save_nestlevel; Relation newIndexRel; LockRelId *lockrelid; Oid tablespaceid; + IndexBuildSecurity ibsec; indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock); heapRel = table_open(indexRel->rd_index->indrelid, ShareUpdateExclusiveLock); /* - * Switch to the table owner's userid, so that any index functions are - * run as that user. Also lock down security-restricted operations - * and arrange to make GUC variable changes local to this command. + * Prevent index functions from doing what they are not supposed to. */ - GetUserIdAndSecContext(&save_userid, &save_sec_context); - SetUserIdAndSecContext(heapRel->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(heapRel->rd_rel->relowner, &ibsec); /* determine safety of this index for set_indexsafe_procflags */ idx->safe = (RelationGetIndexExpressions(indexRel) == NIL && @@ -4188,11 +4172,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein index_close(indexRel, NoLock); index_close(newIndexRel, NoLock); - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); - - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); table_close(heapRel, NoLock); diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c index a74231d8a03..e15c5b82b3c 100644 --- a/src/backend/commands/repack.c +++ b/src/backend/commands/repack.c @@ -484,9 +484,6 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid, Oid tableOid = RelationGetRelid(OldHeap); Relation index; LOCKMODE lmode; - Oid save_userid; - int save_sec_context; - int save_nestlevel; bool verbose = ((params->options & CLUOPT_VERBOSE) != 0); bool recheck = ((params->options & CLUOPT_RECHECK) != 0); bool concurrent = ((params->options & CLUOPT_CONCURRENT) != 0); @@ -522,17 +519,6 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid, /* Report the ordering index even when using a sequential scan and sort. */ pgstat_progress_update_multi_param(2, progress_index, progress_values); - /* - * Switch to the table owner's userid, so that any index 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(OldHeap->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); - /* * Recheck that the relation is still what it was when we started. * @@ -541,7 +527,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid, * not-previously-clustered index. */ if (recheck && - !cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid, + !cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(), lmode, params->options)) goto out; @@ -665,12 +651,6 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid, rebuild_relation(OldHeap, index, verbose, ident_idx); out: - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); - - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); - pgstat_progress_end_command(); } @@ -1090,6 +1070,7 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose, TransactionId frozenXid; MultiXactId cutoffMulti; bool concurrent = OidIsValid(ident_idx); + IndexBuildSecurity ibsec; ChangeContext *chgcxt = NULL; #if USE_ASSERT_CHECKING LOCKMODE lmode; @@ -1100,6 +1081,11 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose, Assert(index == NULL || CheckRelationLockedByMe(index, lmode, false)); #endif + /* + * Prevent index functions from doing what they are not supposed to. + */ + enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec); + if (concurrent) { /* @@ -1305,8 +1291,10 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose, frozenXid, cutoffMulti, relpersistence); } -} + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); +} /* * Create the transient table that will be filled with new data during diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index d8c2f33c615..fe2fbb24af5 100644 --- a/src/backend/commands/vacuum.c +++ b/src/backend/commands/vacuum.c @@ -35,6 +35,7 @@ #include "access/tableam.h" #include "access/transam.h" #include "access/xact.h" +#include "catalog/index.h" #include "catalog/namespace.h" #include "catalog/pg_database.h" #include "catalog/pg_inherits.h" @@ -2037,10 +2038,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params, LockRelId lockrelid; Oid priv_relid; Oid toast_relid; - Oid save_userid; - int save_sec_context; - int save_nestlevel; VacuumParams toast_vacuum_params; + IndexBuildSecurity ibsec; StdRdOptions *relopts; StdRdOptions relopts_copy; @@ -2313,16 +2312,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params, } /* - * Switch to the table owner's userid, so that any index functions are run - * as that user. Also lock down security-restricted operations and - * arrange to make GUC variable changes local to this command. (This is - * unnecessary, but harmless, for lazy VACUUM.) + * Prevent index functions from doing what they are not supposed to. */ - GetUserIdAndSecContext(&save_userid, &save_sec_context); - SetUserIdAndSecContext(rel->rd_rel->relowner, - save_sec_context | SECURITY_RESTRICTED_OPERATION); - save_nestlevel = NewGUCNestLevel(); - RestrictSearchPath(); + enable_index_build_security(rel->rd_rel->relowner, &ibsec); /* * If PROCESS_MAIN is set (the default), it's time to vacuum the main @@ -2353,11 +2345,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params, table_relation_vacuum(rel, ¶ms, bstrategy); } - /* Roll back any GUC changes executed by index functions */ - AtEOXact_GUC(false, save_nestlevel); - - /* Restore userid and security context */ - SetUserIdAndSecContext(save_userid, save_sec_context); + /* Relax the restrictions imposed above. */ + disable_index_build_security(&ibsec); /* all done with this class, but hold lock until commit */ if (rel) diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h index b952ad071d3..0cc5ce3de35 100644 --- a/src/include/catalog/index.h +++ b/src/include/catalog/index.h @@ -173,6 +173,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId, extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags, const ReindexParams *params); +typedef struct IndexBuildSecurity +{ + Oid userid; + int sec_context; + int nestlevel; +} IndexBuildSecurity; + +extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec); +extern void disable_index_build_security(IndexBuildSecurity *sec); + extern bool ReindexIsProcessingHeap(Oid heapOid); extern bool ReindexIsProcessingIndex(Oid indexOid); diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index 5c86d8e98d3..b67998e45b3 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -1304,6 +1304,7 @@ IndexAttachInfo IndexAttrBitmapKind IndexBuildCallback IndexBuildResult +IndexBuildSecurity IndexBulkDeleteCallback IndexBulkDeleteResult IndexClause -- 2.52.0