From 820ab11fbfd508fc75a39c43ad2c1b3e79c4982b Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Mon, 17 Feb 2014 09:33:31 -0500 Subject: [PATCH] Avoid repeated name lookups during table and index DDL. If the name lookups come to different conclusions due to concurrent activity, we might perform some parts of the DDL on a different table than other parts. At least in the case of CREATE INDEX, this can be used to cause the permissions checks to be performed against a different table than the index creation, allowing for a privilege escalation attack. This changes the calling convention for DefineIndex, CreateTrigger, transformIndexStmt, transformAlterTableStmt, CheckIndexCompatible (in 9.2 and newer), and AlterTable (in 9.1 and older). In addition, CheckRelationOwnership is removed in 9.2 and newer and the calling convention is changed in older branches. A field has also been added to the Constraint node (FkConstraint in 8.4). Third-party code calling these functions or using the Constraint node will require updating. Report by Andres Freund. Patch by Robert Haas and Andres Freund, reviewed by Tom Lane. Security: CVE-2014-0062 --- src/backend/bootstrap/bootparse.y | 17 +++- src/backend/catalog/index.c | 10 +- src/backend/catalog/pg_constraint.c | 19 ++++ src/backend/commands/indexcmds.c | 22 +++-- src/backend/commands/tablecmds.c | 137 ++++++++++++++++++++-------- src/backend/commands/trigger.c | 28 +++++- src/backend/nodes/copyfuncs.c | 1 + src/backend/nodes/equalfuncs.c | 1 + src/backend/nodes/outfuncs.c | 1 + src/backend/parser/parse_utilcmd.c | 64 +++++-------- src/backend/tcop/utility.c | 73 +++++---------- src/include/catalog/pg_constraint.h | 1 + src/include/commands/defrem.h | 4 +- src/include/commands/tablecmds.h | 2 + src/include/commands/trigger.h | 2 +- src/include/nodes/parsenodes.h | 2 + src/include/parser/parse_utilcmd.h | 5 +- src/include/tcop/utility.h | 2 - 18 files changed, 234 insertions(+), 157 deletions(-) diff --git a/src/backend/bootstrap/bootparse.y b/src/backend/bootstrap/bootparse.y index f4a1b8f0fd..eeffb0f990 100644 --- a/src/backend/bootstrap/bootparse.y +++ b/src/backend/bootstrap/bootparse.y @@ -27,6 +27,7 @@ #include "bootstrap/bootstrap.h" #include "catalog/catalog.h" #include "catalog/heap.h" +#include "catalog/namespace.h" #include "catalog/pg_am.h" #include "catalog/pg_attribute.h" #include "catalog/pg_authid.h" @@ -281,6 +282,7 @@ Boot_DeclareIndexStmt: XDECLARE INDEX boot_ident oidspec ON boot_ident USING boot_ident LPAREN boot_index_params RPAREN { IndexStmt *stmt = makeNode(IndexStmt); + Oid relationId; do_start(); @@ -302,7 +304,12 @@ Boot_DeclareIndexStmt: stmt->initdeferred = false; stmt->concurrent = false; - DefineIndex(stmt, + /* locks and races need not concern us in bootstrap mode */ + relationId = RangeVarGetRelid(stmt->relation, NoLock, + false); + + DefineIndex(relationId, + stmt, $4, false, false, @@ -316,6 +323,7 @@ Boot_DeclareUniqueIndexStmt: XDECLARE UNIQUE INDEX boot_ident oidspec ON boot_ident USING boot_ident LPAREN boot_index_params RPAREN { IndexStmt *stmt = makeNode(IndexStmt); + Oid relationId; do_start(); @@ -337,7 +345,12 @@ Boot_DeclareUniqueIndexStmt: stmt->initdeferred = false; stmt->concurrent = false; - DefineIndex(stmt, + /* locks and races need not concern us in bootstrap mode */ + relationId = RangeVarGetRelid(stmt->relation, NoLock, + false); + + DefineIndex(relationId, + stmt, $5, false, false, diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 7d6346a6c8..ca8acf321b 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -1202,18 +1202,13 @@ index_constraint_create(Relation heapRelation, */ if (deferrable) { - RangeVar *heapRel; CreateTrigStmt *trigger; - heapRel = makeRangeVar(get_namespace_name(namespaceId), - pstrdup(RelationGetRelationName(heapRelation)), - -1); - trigger = makeNode(CreateTrigStmt); trigger->trigname = (constraintType == CONSTRAINT_PRIMARY) ? "PK_ConstraintTrigger" : "Unique_ConstraintTrigger"; - trigger->relation = heapRel; + trigger->relation = NULL; trigger->funcname = SystemFuncName("unique_key_recheck"); trigger->args = NIL; trigger->row = true; @@ -1226,7 +1221,8 @@ index_constraint_create(Relation heapRelation, trigger->initdeferred = initdeferred; trigger->constrrel = NULL; - (void) CreateTrigger(trigger, NULL, conOid, indexRelationId, true); + (void) CreateTrigger(trigger, NULL, RelationGetRelid(heapRelation), + InvalidOid, conOid, indexRelationId, true); } /* diff --git a/src/backend/catalog/pg_constraint.c b/src/backend/catalog/pg_constraint.c index 107a780964..08a94cfbc7 100644 --- a/src/backend/catalog/pg_constraint.c +++ b/src/backend/catalog/pg_constraint.c @@ -745,6 +745,25 @@ AlterConstraintNamespaces(Oid ownerId, Oid oldNspId, heap_close(conRel, RowExclusiveLock); } +/* + * get_constraint_relation_oids + * Find the IDs of the relations to which a constraint refers. + */ +void +get_constraint_relation_oids(Oid constraint_oid, Oid *conrelid, Oid *confrelid) +{ + HeapTuple tup; + Form_pg_constraint con; + + tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraint_oid)); + if (!HeapTupleIsValid(tup)) /* should not happen */ + elog(ERROR, "cache lookup failed for constraint %u", constraint_oid); + con = (Form_pg_constraint) GETSTRUCT(tup); + *conrelid = con->conrelid; + *confrelid = con->confrelid; + ReleaseSysCache(tup); +} + /* * get_relation_constraint_oid * Find a constraint on the specified relation with the specified name. diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c index f3ee278bb7..ec5fb0da4d 100644 --- a/src/backend/commands/indexcmds.c +++ b/src/backend/commands/indexcmds.c @@ -111,7 +111,6 @@ static void RangeVarCallbackForReindexIndex(const RangeVar *relation, */ bool CheckIndexCompatible(Oid oldId, - RangeVar *heapRelation, char *accessMethodName, List *attributeList, List *exclusionOpNames) @@ -139,7 +138,7 @@ CheckIndexCompatible(Oid oldId, Datum d; /* Caller should already have the relation locked in some way. */ - relationId = RangeVarGetRelid(heapRelation, NoLock, false); + relationId = IndexGetRelation(oldId, false); /* * We can pretend isconstraint = false unconditionally. It only serves to @@ -279,6 +278,8 @@ CheckIndexCompatible(Oid oldId, * DefineIndex * Creates a new index. * + * 'relationId': the OID of the heap relation on which the index is to be + * created * 'stmt': IndexStmt describing the properties of the new index. * 'indexRelationId': normally InvalidOid, but during bootstrap can be * nonzero to specify a preselected OID for the index. @@ -292,7 +293,8 @@ CheckIndexCompatible(Oid oldId, * Returns the OID of the created index. */ Oid -DefineIndex(IndexStmt *stmt, +DefineIndex(Oid relationId, + IndexStmt *stmt, Oid indexRelationId, bool is_alter_table, bool check_rights, @@ -305,7 +307,6 @@ DefineIndex(IndexStmt *stmt, Oid *collationObjectId; Oid *classObjectId; Oid accessMethodId; - Oid relationId; Oid namespaceId; Oid tablespaceId; List *indexColNames; @@ -325,6 +326,7 @@ DefineIndex(IndexStmt *stmt, int n_old_snapshots; LockRelId heaprelid; LOCKTAG heaplocktag; + LOCKMODE lockmode; Snapshot snapshot; int i; @@ -343,14 +345,18 @@ DefineIndex(IndexStmt *stmt, INDEX_MAX_KEYS))); /* - * Open heap relation, acquire a suitable lock on it, remember its OID - * * Only SELECT ... FOR UPDATE/SHARE are allowed while doing a standard * index build; but for concurrent builds we allow INSERT/UPDATE/DELETE * (but not VACUUM). + * + * NB: Caller is responsible for making sure that relationId refers + * to the relation on which the index should be built; except in bootstrap + * mode, this will typically require the caller to have already locked + * the relation. To avoid lock upgrade hazards, that lock should be at + * least as strong as the one we take here. */ - rel = heap_openrv(stmt->relation, - (stmt->concurrent ? ShareUpdateExclusiveLock : ShareLock)); + lockmode = stmt->concurrent ? ShareUpdateExclusiveLock : ShareLock; + rel = heap_open(relationId, lockmode); relationId = RelationGetRelid(rel); namespaceId = RelationGetNamespace(rel); diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 7c1f779d72..bcb81eae88 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -283,7 +283,8 @@ static void validateCheckConstraint(Relation rel, HeapTuple constrtup); static void validateForeignKeyConstraint(char *conname, Relation rel, Relation pkrel, Oid pkindOid, Oid constraintOid); -static void createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, +static void createForeignKeyTriggers(Relation rel, Oid refRelOid, + Constraint *fkconstraint, Oid constraintOid, Oid indexOid); static void ATController(Relation rel, List *cmds, bool recurse, LOCKMODE lockmode); static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, @@ -360,8 +361,9 @@ static void ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, static void ATExecAlterColumnGenericOptions(Relation rel, const char *colName, List *options, LOCKMODE lockmode); static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode); -static void ATPostAlterTypeParse(Oid oldId, char *cmd, - List **wqueue, LOCKMODE lockmode, bool rewrite); +static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, + char *cmd, List **wqueue, LOCKMODE lockmode, + bool rewrite); static void TryReuseIndex(Oid oldId, IndexStmt *stmt); static void TryReuseForeignKey(Oid oldId, Constraint *con); static void change_owner_fix_column_acls(Oid relationOid, @@ -5406,7 +5408,8 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel, /* The IndexStmt has already been through transformIndexStmt */ - new_index = DefineIndex(stmt, + new_index = DefineIndex(RelationGetRelid(rel), + stmt, InvalidOid, /* no predefined OID */ true, /* is_alter_table */ check_rights, @@ -5728,7 +5731,10 @@ ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel, * table; trying to start with a lesser lock will just create a risk of * deadlock.) */ - pkrel = heap_openrv(fkconstraint->pktable, AccessExclusiveLock); + if (OidIsValid(fkconstraint->old_pktable_oid)) + pkrel = heap_open(fkconstraint->old_pktable_oid, AccessExclusiveLock); + else + pkrel = heap_openrv(fkconstraint->pktable, AccessExclusiveLock); /* * Validity checks (permission checks wait till we have the column @@ -6066,7 +6072,8 @@ ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel, /* * Create the triggers that will enforce the constraint. */ - createForeignKeyTriggers(rel, fkconstraint, constrOid, indexOid); + createForeignKeyTriggers(rel, RelationGetRelid(pkrel), fkconstraint, + constrOid, indexOid); /* * Tell Phase 3 to check that the constraint is satisfied by existing @@ -6736,7 +6743,7 @@ validateForeignKeyConstraint(char *conname, } static void -CreateFKCheckTrigger(RangeVar *myRel, Constraint *fkconstraint, +CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, bool on_insert) { CreateTrigStmt *fk_trigger; @@ -6752,7 +6759,7 @@ CreateFKCheckTrigger(RangeVar *myRel, Constraint *fkconstraint, */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->trigname = "RI_ConstraintTrigger_c"; - fk_trigger->relation = myRel; + fk_trigger->relation = NULL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; @@ -6773,10 +6780,11 @@ CreateFKCheckTrigger(RangeVar *myRel, Constraint *fkconstraint, fk_trigger->isconstraint = true; fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; - fk_trigger->constrrel = fkconstraint->pktable; + fk_trigger->constrrel = NULL; fk_trigger->args = NIL; - (void) CreateTrigger(fk_trigger, NULL, constraintOid, indexOid, true); + (void) CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid, constraintOid, + indexOid, true); /* Make changes-so-far visible */ CommandCounterIncrement(); @@ -6786,18 +6794,13 @@ CreateFKCheckTrigger(RangeVar *myRel, Constraint *fkconstraint, * Create the triggers that implement an FK constraint. */ static void -createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, +createForeignKeyTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid) { - RangeVar *myRel; + Oid myRelOid; CreateTrigStmt *fk_trigger; - /* - * Reconstruct a RangeVar for my relation (not passed in, unfortunately). - */ - myRel = makeRangeVar(get_namespace_name(RelationGetNamespace(rel)), - pstrdup(RelationGetRelationName(rel)), - -1); + myRelOid = RelationGetRelid(rel); /* Make changes-so-far visible */ CommandCounterIncrement(); @@ -6808,14 +6811,14 @@ createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->trigname = "RI_ConstraintTrigger_a"; - fk_trigger->relation = fkconstraint->pktable; + fk_trigger->relation = NULL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->events = TRIGGER_TYPE_DELETE; fk_trigger->columns = NIL; fk_trigger->whenClause = NULL; fk_trigger->isconstraint = true; - fk_trigger->constrrel = myRel; + fk_trigger->constrrel = NULL; switch (fkconstraint->fk_del_action) { case FKCONSTR_ACTION_NOACTION: @@ -6850,7 +6853,8 @@ createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, } fk_trigger->args = NIL; - (void) CreateTrigger(fk_trigger, NULL, constraintOid, indexOid, true); + (void) CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid, + indexOid, true); /* Make changes-so-far visible */ CommandCounterIncrement(); @@ -6861,14 +6865,14 @@ createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->trigname = "RI_ConstraintTrigger_a"; - fk_trigger->relation = fkconstraint->pktable; + fk_trigger->relation = NULL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->events = TRIGGER_TYPE_UPDATE; fk_trigger->columns = NIL; fk_trigger->whenClause = NULL; fk_trigger->isconstraint = true; - fk_trigger->constrrel = myRel; + fk_trigger->constrrel = NULL; switch (fkconstraint->fk_upd_action) { case FKCONSTR_ACTION_NOACTION: @@ -6903,7 +6907,8 @@ createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, } fk_trigger->args = NIL; - (void) CreateTrigger(fk_trigger, NULL, constraintOid, indexOid, true); + (void) CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid, + indexOid, true); /* Make changes-so-far visible */ CommandCounterIncrement(); @@ -6912,8 +6917,10 @@ createForeignKeyTriggers(Relation rel, Constraint *fkconstraint, * Build and execute CREATE CONSTRAINT TRIGGER statements for the CHECK * action for both INSERTs and UPDATEs on the referencing table. */ - CreateFKCheckTrigger(myRel, fkconstraint, constraintOid, indexOid, true); - CreateFKCheckTrigger(myRel, fkconstraint, constraintOid, indexOid, false); + CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid, + indexOid, true); + CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid, + indexOid, false); } /* @@ -7832,15 +7839,36 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) * lock on the table the constraint is attached to, and we need to get * that before dropping. It's safe because the parser won't actually look * at the catalogs to detect the existing entry. + * + * We can't rely on the output of deparsing to tell us which relation + * to operate on, because concurrent activity might have made the name + * resolve differently. Instead, we've got to use the OID of the + * constraint or index we're processing to figure out which relation + * to operate on. */ forboth(oid_item, tab->changedConstraintOids, def_item, tab->changedConstraintDefs) - ATPostAlterTypeParse(lfirst_oid(oid_item), (char *) lfirst(def_item), + { + Oid oldId = lfirst_oid(oid_item); + Oid relid; + Oid confrelid; + + get_constraint_relation_oids(oldId, &relid, &confrelid); + ATPostAlterTypeParse(oldId, relid, confrelid, + (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); + } forboth(oid_item, tab->changedIndexOids, def_item, tab->changedIndexDefs) - ATPostAlterTypeParse(lfirst_oid(oid_item), (char *) lfirst(def_item), + { + Oid oldId = lfirst_oid(oid_item); + Oid relid; + + relid = IndexGetRelation(oldId, false); + ATPostAlterTypeParse(oldId, relid, InvalidOid, + (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); + } /* * Now we can drop the existing constraints and indexes --- constraints @@ -7873,12 +7901,13 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) } static void -ATPostAlterTypeParse(Oid oldId, char *cmd, +ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd, List **wqueue, LOCKMODE lockmode, bool rewrite) { List *raw_parsetree_list; List *querytree_list; ListCell *list_item; + Relation rel; /* * We expect that we will get only ALTER TABLE and CREATE INDEX @@ -7894,16 +7923,21 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, if (IsA(stmt, IndexStmt)) querytree_list = lappend(querytree_list, - transformIndexStmt((IndexStmt *) stmt, + transformIndexStmt(oldRelId, + (IndexStmt *) stmt, cmd)); else if (IsA(stmt, AlterTableStmt)) querytree_list = list_concat(querytree_list, - transformAlterTableStmt((AlterTableStmt *) stmt, + transformAlterTableStmt(oldRelId, + (AlterTableStmt *) stmt, cmd)); else querytree_list = lappend(querytree_list, stmt); } + /* Caller should already have acquired whatever lock we need. */ + rel = relation_open(oldRelId, NoLock); + /* * Attach each generated command to the proper place in the work queue. * Note this could result in creation of entirely new work-queue entries. @@ -7915,7 +7949,6 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, foreach(list_item, querytree_list) { Node *stm = (Node *) lfirst(list_item); - Relation rel; AlteredTableInfo *tab; switch (nodeTag(stm)) @@ -7928,14 +7961,12 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, if (!rewrite) TryReuseIndex(oldId, stmt); - rel = relation_openrv(stmt->relation, lockmode); tab = ATGetQueueEntry(wqueue, rel); newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_ReAddIndex; newcmd->def = (Node *) stmt; tab->subcmds[AT_PASS_OLD_INDEX] = lappend(tab->subcmds[AT_PASS_OLD_INDEX], newcmd); - relation_close(rel, NoLock); break; } case T_AlterTableStmt: @@ -7943,7 +7974,6 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, AlterTableStmt *stmt = (AlterTableStmt *) stm; ListCell *lcmd; - rel = relation_openrv(stmt->relation, lockmode); tab = ATGetQueueEntry(wqueue, rel); foreach(lcmd, stmt->cmds) { @@ -7964,6 +7994,7 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, case AT_AddConstraint: Assert(IsA(cmd->def, Constraint)); con = (Constraint *) cmd->def; + con->old_pktable_oid = refRelId; /* rewriting neither side of a FK */ if (con->contype == CONSTR_FOREIGN && !rewrite && !tab->rewrite) @@ -7977,7 +8008,6 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, (int) cmd->subtype); } } - relation_close(rel, NoLock); break; } default: @@ -7985,6 +8015,8 @@ ATPostAlterTypeParse(Oid oldId, char *cmd, (int) nodeTag(stm)); } } + + relation_close(rel, NoLock); } /* @@ -7995,7 +8027,6 @@ static void TryReuseIndex(Oid oldId, IndexStmt *stmt) { if (CheckIndexCompatible(oldId, - stmt->relation, stmt->accessMethod, stmt->indexParams, stmt->excludeOpNames)) @@ -10290,6 +10321,38 @@ RangeVarCallbackOwnsTable(const RangeVar *relation, aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, relation->relname); } +/* + * Callback to RangeVarGetRelidExtended(), similar to + * RangeVarCallbackOwnsTable() but without checks on the type of the relation. + */ +void +RangeVarCallbackOwnsRelation(const RangeVar *relation, + Oid relId, Oid oldRelId, void *arg) +{ + HeapTuple tuple; + + /* Nothing to do if the relation was not found. */ + if (!OidIsValid(relId)) + return; + + tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId)); + if (!HeapTupleIsValid(tuple)) /* should not happen */ + elog(ERROR, "cache lookup failed for relation %u", relId); + + if (!pg_class_ownercheck(relId, GetUserId())) + aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, + relation->relname); + + if (!allowSystemTableMods && + IsSystemClass((Form_pg_class) GETSTRUCT(tuple))) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("permission denied: \"%s\" is a system catalog", + relation->relname))); + + ReleaseSysCache(tuple); +} + /* * Common RangeVarGetRelid callback for rename, set schema, and alter table * processing. diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index f546d9426f..9e6c9549c2 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -42,6 +42,7 @@ #include "pgstat.h" #include "rewrite/rewriteManip.h" #include "storage/bufmgr.h" +#include "storage/lmgr.h" #include "tcop/utility.h" #include "utils/acl.h" #include "utils/builtins.h" @@ -94,6 +95,13 @@ static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo, * queryString is the source text of the CREATE TRIGGER command. * This must be supplied if a whenClause is specified, else it can be NULL. * + * relOid, if nonzero, is the relation on which the trigger should be + * created. If zero, the name provided in the statement will be looked up. + * + * refRelOid, if nonzero, is the relation to which the constraint trigger + * refers. If zero, the constraint relation name provided in the statement + * will be looked up as needed. + * * constraintOid, if nonzero, says that this trigger is being created * internally to implement that constraint. A suitable pg_depend entry will * be made to link the trigger to that constraint. constraintOid is zero when @@ -116,7 +124,7 @@ static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo, */ Oid CreateTrigger(CreateTrigStmt *stmt, const char *queryString, - Oid constraintOid, Oid indexOid, + Oid relOid, Oid refRelOid, Oid constraintOid, Oid indexOid, bool isInternal) { int16 tgtype; @@ -145,7 +153,10 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, ObjectAddress myself, referenced; - rel = heap_openrv(stmt->relation, AccessExclusiveLock); + if (OidIsValid(relOid)) + rel = heap_open(relOid, AccessExclusiveLock); + else + rel = heap_openrv(stmt->relation, AccessExclusiveLock); /* * Triggers must be on tables or views, and there are additional @@ -194,7 +205,7 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(rel)))); - if (stmt->isconstraint && stmt->constrrel != NULL) + if (stmt->isconstraint) { /* * We must take a lock on the target relation to protect against @@ -203,7 +214,14 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, * might end up creating a pg_constraint entry referencing a * nonexistent table. */ - constrrelid = RangeVarGetRelid(stmt->constrrel, AccessShareLock, false); + if (OidIsValid(refRelOid)) + { + LockRelationOid(refRelOid, AccessShareLock); + constrrelid = refRelOid; + } + else if (stmt->constrrel != NULL) + constrrelid = RangeVarGetRelid(stmt->constrrel, AccessShareLock, + false); } /* permission checks */ @@ -513,7 +531,7 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("trigger \"%s\" for relation \"%s\" already exists", - trigname, stmt->relation->relname))); + trigname, RelationGetRelationName(rel)))); } systable_endscan(tgscan); } diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index 9bac99452d..dbe0f6a960 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -2357,6 +2357,7 @@ _copyConstraint(const Constraint *from) COPY_SCALAR_FIELD(fk_upd_action); COPY_SCALAR_FIELD(fk_del_action); COPY_NODE_FIELD(old_conpfeqop); + COPY_SCALAR_FIELD(old_pktable_oid); COPY_SCALAR_FIELD(skip_validation); COPY_SCALAR_FIELD(initially_valid); diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c index d185654f71..f8770b0b61 100644 --- a/src/backend/nodes/equalfuncs.c +++ b/src/backend/nodes/equalfuncs.c @@ -2143,6 +2143,7 @@ _equalConstraint(const Constraint *a, const Constraint *b) COMPARE_SCALAR_FIELD(fk_upd_action); COMPARE_SCALAR_FIELD(fk_del_action); COMPARE_NODE_FIELD(old_conpfeqop); + COMPARE_SCALAR_FIELD(old_pktable_oid); COMPARE_SCALAR_FIELD(skip_validation); COMPARE_SCALAR_FIELD(initially_valid); diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 1df71f6479..888ffd2126 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -2653,6 +2653,7 @@ _outConstraint(StringInfo str, const Constraint *node) WRITE_CHAR_FIELD(fk_upd_action); WRITE_CHAR_FIELD(fk_del_action); WRITE_NODE_FIELD(old_conpfeqop); + WRITE_OID_FIELD(old_pktable_oid); WRITE_BOOL_FIELD(skip_validation); WRITE_BOOL_FIELD(initially_valid); break; diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c index e3f9c62b2a..5df939a5b3 100644 --- a/src/backend/parser/parse_utilcmd.c +++ b/src/backend/parser/parse_utilcmd.c @@ -1867,14 +1867,18 @@ transformFKConstraints(CreateStmtContext *cxt, * a predicate expression. There are several code paths that create indexes * without bothering to call this, because they know they don't have any * such expressions to deal with. + * + * To avoid race conditions, it's important that this function rely only on + * the passed-in relid (and not on stmt->relation) to determine the target + * relation. */ IndexStmt * -transformIndexStmt(IndexStmt *stmt, const char *queryString) +transformIndexStmt(Oid relid, IndexStmt *stmt, const char *queryString) { - Relation rel; ParseState *pstate; RangeTblEntry *rte; ListCell *l; + Relation rel; /* * We must not scribble on the passed-in IndexStmt, so copy it. (This is @@ -1882,26 +1886,17 @@ transformIndexStmt(IndexStmt *stmt, const char *queryString) */ stmt = (IndexStmt *) copyObject(stmt); - /* - * Open the parent table with appropriate locking. We must do this - * because addRangeTableEntry() would acquire only AccessShareLock, - * leaving DefineIndex() needing to do a lock upgrade with consequent risk - * of deadlock. Make sure this stays in sync with the type of lock - * DefineIndex() wants. If we are being called by ALTER TABLE, we will - * already hold a higher lock. - */ - rel = heap_openrv(stmt->relation, - (stmt->concurrent ? ShareUpdateExclusiveLock : ShareLock)); - /* Set up pstate */ pstate = make_parsestate(NULL); pstate->p_sourcetext = queryString; /* * Put the parent table into the rtable so that the expressions can refer - * to its fields without qualification. + * to its fields without qualification. Caller is responsible for locking + * relation, but we still need to open it. */ - rte = addRangeTableEntry(pstate, stmt->relation, NULL, false, true); + rel = relation_open(relid, NoLock); + rte = addRangeTableEntryForRelation(pstate, rel, NULL, false, true); /* no to join list, yes to namespaces */ addRTEtoQuery(pstate, rte, false, true, true); @@ -1955,7 +1950,7 @@ transformIndexStmt(IndexStmt *stmt, const char *queryString) free_parsestate(pstate); - /* Close relation, but keep the lock */ + /* Close relation */ heap_close(rel, NoLock); return stmt; @@ -2277,9 +2272,14 @@ transformRuleStmt(RuleStmt *stmt, const char *queryString, * Returns a List of utility commands to be done in sequence. One of these * will be the transformed AlterTableStmt, but there may be additional actions * to be done before and after the actual AlterTable() call. + * + * To avoid race conditions, it's important that this function rely only on + * the passed-in relid (and not on stmt->relation) to determine the target + * relation. */ List * -transformAlterTableStmt(AlterTableStmt *stmt, const char *queryString) +transformAlterTableStmt(Oid relid, AlterTableStmt *stmt, + const char *queryString) { Relation rel; ParseState *pstate; @@ -2291,7 +2291,6 @@ transformAlterTableStmt(AlterTableStmt *stmt, const char *queryString) List *newcmds = NIL; bool skipValidation = true; AlterTableCmd *newcmd; - LOCKMODE lockmode; /* * We must not scribble on the passed-in AlterTableStmt, so copy it. (This @@ -2299,29 +2298,8 @@ transformAlterTableStmt(AlterTableStmt *stmt, const char *queryString) */ stmt = (AlterTableStmt *) copyObject(stmt); - /* - * Determine the appropriate lock level for this list of subcommands. - */ - lockmode = AlterTableGetLockLevel(stmt->cmds); - - /* - * Acquire appropriate lock on the target relation, which will be held - * until end of transaction. This ensures any decisions we make here - * based on the state of the relation will still be good at execution. We - * must get lock now because execution will later require it; taking a - * lower grade lock now and trying to upgrade later risks deadlock. Any - * new commands we add after this must not upgrade the lock level - * requested here. - */ - rel = relation_openrv_extended(stmt->relation, lockmode, stmt->missing_ok); - if (rel == NULL) - { - /* this message is consistent with relation_openrv */ - ereport(NOTICE, - (errmsg("relation \"%s\" does not exist, skipping", - stmt->relation->relname))); - return NIL; - } + /* Caller is responsible for locking the relation */ + rel = relation_open(relid, NoLock); /* Set up pstate and CreateStmtContext */ pstate = make_parsestate(NULL); @@ -2434,7 +2412,7 @@ transformAlterTableStmt(AlterTableStmt *stmt, const char *queryString) IndexStmt *idxstmt = (IndexStmt *) lfirst(l); Assert(IsA(idxstmt, IndexStmt)); - idxstmt = transformIndexStmt(idxstmt, queryString); + idxstmt = transformIndexStmt(relid, idxstmt, queryString); newcmd = makeNode(AlterTableCmd); newcmd->subtype = OidIsValid(idxstmt->indexOid) ? AT_AddIndexConstraint : AT_AddIndex; newcmd->def = (Node *) idxstmt; @@ -2458,7 +2436,7 @@ transformAlterTableStmt(AlterTableStmt *stmt, const char *queryString) newcmds = lappend(newcmds, newcmd); } - /* Close rel but keep lock */ + /* Close rel */ relation_close(rel, NoLock); /* diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 509bf4d3d8..7903e03d05 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -66,49 +66,6 @@ ProcessUtility_hook_type ProcessUtility_hook = NULL; -/* - * Verify user has ownership of specified relation, else ereport. - * - * If noCatalogs is true then we also deny access to system catalogs, - * except when allowSystemTableMods is true. - */ -void -CheckRelationOwnership(RangeVar *rel, bool noCatalogs) -{ - Oid relOid; - HeapTuple tuple; - - /* - * XXX: This is unsafe in the presence of concurrent DDL, since it is - * called before acquiring any lock on the target relation. However, - * locking the target relation (especially using something like - * AccessExclusiveLock) before verifying that the user has permissions is - * not appealing either. - */ - relOid = RangeVarGetRelid(rel, NoLock, false); - - tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid)); - if (!HeapTupleIsValid(tuple)) /* should not happen */ - elog(ERROR, "cache lookup failed for relation %u", relOid); - - if (!pg_class_ownercheck(relOid, GetUserId())) - aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, - rel->relname); - - if (noCatalogs) - { - if (!allowSystemTableMods && - IsSystemClass((Form_pg_class) GETSTRUCT(tuple))) - ereport(ERROR, - (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), - errmsg("permission denied: \"%s\" is a system catalog", - rel->relname))); - } - - ReleaseSysCache(tuple); -} - - /* * CommandIsReadOnly: is an executable query read-only? * @@ -723,7 +680,8 @@ standard_ProcessUtility(Node *parsetree, if (OidIsValid(relid)) { /* Run parse analysis ... */ - stmts = transformAlterTableStmt(atstmt, queryString); + stmts = transformAlterTableStmt(relid, atstmt, + queryString); /* ... and do it */ foreach(l, stmts) @@ -910,18 +868,36 @@ standard_ProcessUtility(Node *parsetree, case T_IndexStmt: /* CREATE INDEX */ { IndexStmt *stmt = (IndexStmt *) parsetree; + Oid relid; + LOCKMODE lockmode; if (stmt->concurrent) PreventTransactionChain(isTopLevel, "CREATE INDEX CONCURRENTLY"); - CheckRelationOwnership(stmt->relation, true); + /* + * Look up the relation OID just once, right here at the + * beginning, so that we don't end up repeating the name + * lookup later and latching onto a different relation + * partway through. To avoid lock upgrade hazards, it's + * important that we take the strongest lock that will + * eventually be needed here, so the lockmode calculation + * needs to match what DefineIndex() does. + */ + lockmode = stmt->concurrent ? ShareUpdateExclusiveLock + : ShareLock; + relid = + RangeVarGetRelidExtended(stmt->relation, lockmode, + false, false, + RangeVarCallbackOwnsRelation, + NULL); /* Run parse analysis ... */ - stmt = transformIndexStmt(stmt, queryString); + stmt = transformIndexStmt(relid, stmt, queryString); /* ... and do it */ - DefineIndex(stmt, + DefineIndex(relid, /* OID of heap relation */ + stmt, InvalidOid, /* no predefined OID */ false, /* is_alter_table */ true, /* check_rights */ @@ -1057,7 +1033,8 @@ standard_ProcessUtility(Node *parsetree, case T_CreateTrigStmt: (void) CreateTrigger((CreateTrigStmt *) parsetree, queryString, - InvalidOid, InvalidOid, false); + InvalidOid, InvalidOid, InvalidOid, + InvalidOid, false); break; case T_CreatePLangStmt: diff --git a/src/include/catalog/pg_constraint.h b/src/include/catalog/pg_constraint.h index d9d40b2687..d8f8da411b 100644 --- a/src/include/catalog/pg_constraint.h +++ b/src/include/catalog/pg_constraint.h @@ -246,6 +246,7 @@ extern char *ChooseConstraintName(const char *name1, const char *name2, extern void AlterConstraintNamespaces(Oid ownerId, Oid oldNspId, Oid newNspId, bool isType, ObjectAddresses *objsMoved); +extern void get_constraint_relation_oids(Oid constraint_oid, Oid *conrelid, Oid *confrelid); extern Oid get_relation_constraint_oid(Oid relid, const char *conname, bool missing_ok); extern Oid get_domain_constraint_oid(Oid typid, const char *conname, bool missing_ok); diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h index 9b6d57a21e..a00fd37620 100644 --- a/src/include/commands/defrem.h +++ b/src/include/commands/defrem.h @@ -20,7 +20,8 @@ extern void RemoveObjects(DropStmt *stmt); /* commands/indexcmds.c */ -extern Oid DefineIndex(IndexStmt *stmt, +extern Oid DefineIndex(Oid relationId, + IndexStmt *stmt, Oid indexRelationId, bool is_alter_table, bool check_rights, @@ -35,7 +36,6 @@ extern char *makeObjectName(const char *name1, const char *name2, extern char *ChooseRelationName(const char *name1, const char *name2, const char *label, Oid namespaceid); extern bool CheckIndexCompatible(Oid oldId, - RangeVar *heapRelation, char *accessMethodName, List *attributeList, List *exclusionOpNames); diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h index 4f32062056..d41f8a1dc6 100644 --- a/src/include/commands/tablecmds.h +++ b/src/include/commands/tablecmds.h @@ -78,4 +78,6 @@ extern void AtEOSubXact_on_commit_actions(bool isCommit, extern void RangeVarCallbackOwnsTable(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg); +extern void RangeVarCallbackOwnsRelation(const RangeVar *relation, + Oid relId, Oid oldRelId, void *noCatalogs); #endif /* TABLECMDS_H */ diff --git a/src/include/commands/trigger.h b/src/include/commands/trigger.h index 93033414d9..0869c0bc5f 100644 --- a/src/include/commands/trigger.h +++ b/src/include/commands/trigger.h @@ -109,7 +109,7 @@ extern PGDLLIMPORT int SessionReplicationRole; #define TRIGGER_DISABLED 'D' extern Oid CreateTrigger(CreateTrigStmt *stmt, const char *queryString, - Oid constraintOid, Oid indexOid, + Oid relOid, Oid refRelOid, Oid constraintOid, Oid indexOid, bool isInternal); extern void RemoveTriggerById(Oid trigOid); diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 327f7cf074..31f5479da3 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -1566,6 +1566,8 @@ typedef struct Constraint /* Fields used for constraints that allow a NOT VALID specification */ bool skip_validation; /* skip validation of existing rows? */ bool initially_valid; /* mark the new constraint as valid? */ + + Oid old_pktable_oid; /* pg_constraint.confrelid of my former self */ } Constraint; /* ---------------------- diff --git a/src/include/parser/parse_utilcmd.h b/src/include/parser/parse_utilcmd.h index 4ad793a43b..d8b340ef01 100644 --- a/src/include/parser/parse_utilcmd.h +++ b/src/include/parser/parse_utilcmd.h @@ -18,9 +18,10 @@ extern List *transformCreateStmt(CreateStmt *stmt, const char *queryString); -extern List *transformAlterTableStmt(AlterTableStmt *stmt, +extern List *transformAlterTableStmt(Oid relid, AlterTableStmt *stmt, const char *queryString); -extern IndexStmt *transformIndexStmt(IndexStmt *stmt, const char *queryString); +extern IndexStmt *transformIndexStmt(Oid relid, IndexStmt *stmt, + const char *queryString); extern void transformRuleStmt(RuleStmt *stmt, const char *queryString, List **actions, Node **whereClause); extern List *transformCreateSchemaStmt(CreateSchemaStmt *stmt); diff --git a/src/include/tcop/utility.h b/src/include/tcop/utility.h index 54190b2f6c..ae871cacad 100644 --- a/src/include/tcop/utility.h +++ b/src/include/tcop/utility.h @@ -42,6 +42,4 @@ extern LogStmtLevel GetCommandLogLevel(Node *parsetree); extern bool CommandIsReadOnly(Node *parsetree); -extern void CheckRelationOwnership(RangeVar *rel, bool noCatalogs); - #endif /* UTILITY_H */ -- 2.40.0