From 85454829475451a095c695e8cd552791e488f89c Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 31 Oct 2003 20:00:49 +0000
Subject: [PATCH] When a superuser does GRANT or REVOKE on an object he doesn't
own, process the command as though it were issued by the object owner. This
prevents creating weird scenarios in which the same privileges may appear to
flow from different sources, and ensures that a superuser can in fact revoke
all privileges if he wants to. In particular this means that the regression
tests work when run by a superuser other than the original bootstrap userid.
Per report from Larry Rosenman.
---
doc/src/sgml/ref/grant.sgml | 31 +++++---
doc/src/sgml/ref/revoke.sgml | 24 ++++--
src/backend/catalog/aclchk.c | 147 +++++++++++++++++++++++------------
3 files changed, 135 insertions(+), 67 deletions(-)
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index b2ad6310525..a43de6356d9 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/grant.sgml,v 1.36 2003/09/20 20:12:05 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/grant.sgml,v 1.37 2003/10/31 20:00:48 tgl Exp $
PostgreSQL documentation
-->
@@ -66,19 +66,21 @@ GRANT { { CREATE | USAGE } [,...] | ALL [ PRIVILEGES ] }
</para>
<para>
- There is no need to grant privileges to the owner of an object (usually the user that created it),
- as the owner has all privileges by default. (The owner could,
- however, choose to revoke some of his own privileges for safety.)
- The right to drop an object, or to alter it in any way is
- not described by a grantable right; it is inherent in the owner,
- and cannot be granted or revoked.
+ If <literal>WITH GRANT OPTION</literal> is specified, the recipient
+ of the privilege may in turn grant it to others. By default this
+ is not allowed. Grant options can only be granted to individual
+ users, not to groups or <literal>PUBLIC</literal>.
</para>
<para>
- If <literal>WITH GRANT OPTION</literal> is specified, the recipient
- of the privilege may in turn grant it to others. By default this
- is not possible. Grant options can only be granted to individual
- users, not groups or <literal>PUBLIC</literal>.
+ There is no need to grant privileges to the owner of an object
+ (usually the user that created it),
+ as the owner has all privileges by default. (The owner could,
+ however, choose to revoke some of his own privileges for safety.)
+ The right to drop an object, or to alter its definition in any way is
+ not described by a grantable privilege; it is inherent in the owner,
+ and cannot be granted or revoked. It is not possible for the owner's
+ grant options to be revoked, either.
</para>
<para>
@@ -263,6 +265,13 @@ GRANT { { CREATE | USAGE } [,...] | ALL [ PRIVILEGES ] }
except when absolutely necessary.
</para>
+ <para>
+ If a superuser chooses to issue a <command>GRANT</> or <command>REVOKE</>
+ command, the command is performed as though it were issued by the
+ owner of the affected object. In particular, privileges granted via
+ such a command will appear to have been granted by the object owner.
+ </para>
+
<para>
Currently, to grant privileges in <productname>PostgreSQL</productname>
to only a few columns, you must
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 557a219f773..cb69c707b7a 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/revoke.sgml,v 1.27 2003/08/31 17:32:24 petere Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/revoke.sgml,v 1.28 2003/10/31 20:00:48 tgl Exp $
PostgreSQL documentation
-->
@@ -63,6 +63,11 @@ REVOKE [ GRANT OPTION FOR ]
all users.
</para>
+ <para>
+ See the description of the <xref linkend="sql-grant" endterm="sql-grant-title"> command for
+ the meaning of the privilege types.
+ </para>
+
<para>
Note that any particular user will have the sum
of privileges granted directly to him, privileges granted to any group he
@@ -73,11 +78,6 @@ REVOKE [ GRANT OPTION FOR ]
directly or via a group will still have it.
</para>
- <para>
- See the description of the <xref linkend="sql-grant" endterm="sql-grant-title"> command for
- the meaning of the privilege types.
- </para>
-
<para>
If <literal>GRANT OPTION FOR</literal> is specified, only the grant
option for the privilege is revoked, not the privilege itself.
@@ -116,6 +116,15 @@ REVOKE [ GRANT OPTION FOR ]
the <literal>CASCADE</literal> option so that the privilege is
automatically revoked from user C.
</para>
+
+ <para>
+ If a superuser chooses to issue a <command>GRANT</> or <command>REVOKE</>
+ command, the command is performed as though it were issued by the
+ owner of the affected object. Since all privileges ultimately come
+ from the object owner (possibly indirectly via chains of grant options),
+ it is possible for a superuser to revoke all privileges, but this may
+ require use of <literal>CASCADE</literal> as stated above.
+ </para>
</refsect1>
<refsect1 id="SQL-REVOKE-examples">
@@ -153,7 +162,8 @@ REVOKE [ GRANT OPTION FOR ] <replaceable class="PARAMETER">privileges</replaceab
{ RESTRICT | CASCADE }
</synopsis>
One of <literal>RESTRICT</literal> or <literal>CASCADE</literal>
- is required.
+ is required according to the standard, but <productname>PostgreSQL</>
+ assumes <literal>RESTRICT</literal> by default.
</para>
</refsect1>
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 437453a03be..bf43769d706 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/catalog/aclchk.c,v 1.90 2003/10/29 22:20:54 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/catalog/aclchk.c,v 1.91 2003/10/31 20:00:49 tgl Exp $
*
* NOTES
* See acl.h.
@@ -68,6 +68,32 @@ dumpacl(Acl *acl)
#endif /* ACLDEBUG */
+/*
+ * Determine the effective grantor ID for a GRANT or REVOKE operation.
+ *
+ * Ordinarily this is just the current user, but when a superuser does
+ * GRANT or REVOKE, we pretend he is the object owner. This ensures that
+ * all granted privileges appear to flow from the object owner, and there
+ * are never multiple "original sources" of a privilege.
+ */
+static AclId
+select_grantor(AclId ownerId)
+{
+ AclId grantorId;
+
+ grantorId = GetUserId();
+
+ /* fast path if no difference */
+ if (grantorId == ownerId)
+ return grantorId;
+
+ if (superuser())
+ grantorId = ownerId;
+
+ return grantorId;
+}
+
+
/*
* If is_grant is true, adds the given privileges for the list of
* grantees to the existing old_acl. If is_grant is false, the
@@ -77,9 +103,9 @@ dumpacl(Acl *acl)
*/
static Acl *
merge_acl_with_grant(Acl *old_acl, bool is_grant,
- List *grantees, AclMode privileges,
bool grant_option, DropBehavior behavior,
- AclId owner_uid)
+ List *grantees, AclMode privileges,
+ AclId grantor_uid, AclId owner_uid)
{
unsigned modechg;
List *j;
@@ -128,7 +154,7 @@ merge_acl_with_grant(Acl *old_acl, bool is_grant,
* and later the user is removed from the group, the situation is
* impossible to clean up.
*/
- if (is_grant && idtype != ACL_IDTYPE_UID && grant_option)
+ if (is_grant && grant_option && idtype != ACL_IDTYPE_UID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_GRANT_OPERATION),
errmsg("grant options can only be granted to individual users")));
@@ -138,7 +164,7 @@ merge_acl_with_grant(Acl *old_acl, bool is_grant,
(errcode(ERRCODE_INVALID_GRANT_OPERATION),
errmsg("cannot revoke grant options from owner")));
- aclitem.ai_grantor = GetUserId();
+ aclitem.ai_grantor = grantor_uid;
ACLITEM_SET_PRIVS_IDTYPE(aclitem,
(is_grant || !grant_option) ? privileges : ACL_NO_RIGHTS,
@@ -224,6 +250,8 @@ ExecuteGrantStmt_Relation(GrantStmt *stmt)
bool isNull;
Acl *old_acl;
Acl *new_acl;
+ AclId grantorId;
+ AclId ownerId;
HeapTuple newtuple;
Datum values[Natts_pg_class];
char nulls[Natts_pg_class];
@@ -239,9 +267,13 @@ ExecuteGrantStmt_Relation(GrantStmt *stmt)
elog(ERROR, "cache lookup failed for relation %u", relOid);
pg_class_tuple = (Form_pg_class) GETSTRUCT(tuple);
+ ownerId = pg_class_tuple->relowner;
+ grantorId = select_grantor(ownerId);
+
if (stmt->is_grant
&& !pg_class_ownercheck(relOid, GetUserId())
- && pg_class_aclcheck(relOid, GetUserId(), ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
+ && pg_class_aclcheck(relOid, GetUserId(),
+ ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS, relvar->relname);
/* Not sensible to grant on an index */
@@ -252,22 +284,20 @@ ExecuteGrantStmt_Relation(GrantStmt *stmt)
relvar->relname)));
/*
- * If there's no ACL, create a default using the pg_class.relowner
- * field.
+ * If there's no ACL, substitute the proper default.
*/
aclDatum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relacl,
&isNull);
if (isNull)
- old_acl = acldefault(ACL_OBJECT_RELATION,
- pg_class_tuple->relowner);
+ old_acl = acldefault(ACL_OBJECT_RELATION, ownerId);
else
/* get a detoasted copy of the ACL */
old_acl = DatumGetAclPCopy(aclDatum);
new_acl = merge_acl_with_grant(old_acl, stmt->is_grant,
- stmt->grantees, privileges,
stmt->grant_option, stmt->behavior,
- pg_class_tuple->relowner);
+ stmt->grantees, privileges,
+ grantorId, ownerId);
/* finished building new ACL value, now insert it */
MemSet(values, 0, sizeof(values));
@@ -328,6 +358,8 @@ ExecuteGrantStmt_Database(GrantStmt *stmt)
bool isNull;
Acl *old_acl;
Acl *new_acl;
+ AclId grantorId;
+ AclId ownerId;
HeapTuple newtuple;
Datum values[Natts_pg_database];
char nulls[Natts_pg_database];
@@ -345,28 +377,31 @@ ExecuteGrantStmt_Database(GrantStmt *stmt)
errmsg("database \"%s\" does not exist", dbname)));
pg_database_tuple = (Form_pg_database) GETSTRUCT(tuple);
+ ownerId = pg_database_tuple->datdba;
+ grantorId = select_grantor(ownerId);
+
if (stmt->is_grant
- && pg_database_tuple->datdba != GetUserId()
- && pg_database_aclcheck(HeapTupleGetOid(tuple), GetUserId(), ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
+ && !pg_database_ownercheck(HeapTupleGetOid(tuple), GetUserId())
+ && pg_database_aclcheck(HeapTupleGetOid(tuple), GetUserId(),
+ ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_DATABASE,
NameStr(pg_database_tuple->datname));
/*
- * If there's no ACL, create a default.
+ * If there's no ACL, substitute the proper default.
*/
aclDatum = heap_getattr(tuple, Anum_pg_database_datacl,
RelationGetDescr(relation), &isNull);
if (isNull)
- old_acl = acldefault(ACL_OBJECT_DATABASE,
- pg_database_tuple->datdba);
+ old_acl = acldefault(ACL_OBJECT_DATABASE, ownerId);
else
/* get a detoasted copy of the ACL */
old_acl = DatumGetAclPCopy(aclDatum);
new_acl = merge_acl_with_grant(old_acl, stmt->is_grant,
- stmt->grantees, privileges,
stmt->grant_option, stmt->behavior,
- pg_database_tuple->datdba);
+ stmt->grantees, privileges,
+ grantorId, ownerId);
/* finished building new ACL value, now insert it */
MemSet(values, 0, sizeof(values));
@@ -426,6 +461,8 @@ ExecuteGrantStmt_Function(GrantStmt *stmt)
bool isNull;
Acl *old_acl;
Acl *new_acl;
+ AclId grantorId;
+ AclId ownerId;
HeapTuple newtuple;
Datum values[Natts_pg_proc];
char nulls[Natts_pg_proc];
@@ -441,29 +478,31 @@ ExecuteGrantStmt_Function(GrantStmt *stmt)
elog(ERROR, "cache lookup failed for function %u", oid);
pg_proc_tuple = (Form_pg_proc) GETSTRUCT(tuple);
+ ownerId = pg_proc_tuple->proowner;
+ grantorId = select_grantor(ownerId);
+
if (stmt->is_grant
&& !pg_proc_ownercheck(oid, GetUserId())
- && pg_proc_aclcheck(oid, GetUserId(), ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
+ && pg_proc_aclcheck(oid, GetUserId(),
+ ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_PROC,
NameStr(pg_proc_tuple->proname));
/*
- * If there's no ACL, create a default using the pg_proc.proowner
- * field.
+ * If there's no ACL, substitute the proper default.
*/
aclDatum = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_proacl,
&isNull);
if (isNull)
- old_acl = acldefault(ACL_OBJECT_FUNCTION,
- pg_proc_tuple->proowner);
+ old_acl = acldefault(ACL_OBJECT_FUNCTION, ownerId);
else
/* get a detoasted copy of the ACL */
old_acl = DatumGetAclPCopy(aclDatum);
new_acl = merge_acl_with_grant(old_acl, stmt->is_grant,
- stmt->grantees, privileges,
stmt->grant_option, stmt->behavior,
- pg_proc_tuple->proowner);
+ stmt->grantees, privileges,
+ grantorId, ownerId);
/* finished building new ACL value, now insert it */
MemSet(values, 0, sizeof(values));
@@ -522,6 +561,8 @@ ExecuteGrantStmt_Language(GrantStmt *stmt)
bool isNull;
Acl *old_acl;
Acl *new_acl;
+ AclId grantorId;
+ AclId ownerId;
HeapTuple newtuple;
Datum values[Natts_pg_language];
char nulls[Natts_pg_language];
@@ -537,36 +578,40 @@ ExecuteGrantStmt_Language(GrantStmt *stmt)
errmsg("language \"%s\" does not exist", langname)));
pg_language_tuple = (Form_pg_language) GETSTRUCT(tuple);
- if (!pg_language_tuple->lanpltrusted && stmt->is_grant)
- ereport(ERROR,
- (errcode(ERRCODE_WRONG_OBJECT_TYPE),
- errmsg("language \"%s\" is not trusted", langname)));
+ /*
+ * Note: for now, languages are treated as owned by the bootstrap
+ * user. We should add an owner column to pg_language instead.
+ */
+ ownerId = BOOTSTRAP_USESYSID;
+ grantorId = select_grantor(ownerId);
if (stmt->is_grant
- && !superuser()
- && pg_language_aclcheck(HeapTupleGetOid(tuple), GetUserId(), ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
+ && !superuser() /* XXX no ownercheck() available */
+ && pg_language_aclcheck(HeapTupleGetOid(tuple), GetUserId(),
+ ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_LANGUAGE,
NameStr(pg_language_tuple->lanname));
+ if (!pg_language_tuple->lanpltrusted && stmt->is_grant)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("language \"%s\" is not trusted", langname)));
+
/*
- * If there's no ACL, create a default.
- *
- * Note: for now, languages are treated as owned by the bootstrap
- * user. We should add an owner column to pg_language instead.
+ * If there's no ACL, substitute the proper default.
*/
aclDatum = SysCacheGetAttr(LANGNAME, tuple, Anum_pg_language_lanacl,
&isNull);
if (isNull)
- old_acl = acldefault(ACL_OBJECT_LANGUAGE,
- BOOTSTRAP_USESYSID);
+ old_acl = acldefault(ACL_OBJECT_LANGUAGE, ownerId);
else
/* get a detoasted copy of the ACL */
old_acl = DatumGetAclPCopy(aclDatum);
new_acl = merge_acl_with_grant(old_acl, stmt->is_grant,
- stmt->grantees, privileges,
stmt->grant_option, stmt->behavior,
- BOOTSTRAP_USESYSID);
+ stmt->grantees, privileges,
+ grantorId, ownerId);
/* finished building new ACL value, now insert it */
MemSet(values, 0, sizeof(values));
@@ -625,6 +670,8 @@ ExecuteGrantStmt_Namespace(GrantStmt *stmt)
bool isNull;
Acl *old_acl;
Acl *new_acl;
+ AclId grantorId;
+ AclId ownerId;
HeapTuple newtuple;
Datum values[Natts_pg_namespace];
char nulls[Natts_pg_namespace];
@@ -640,30 +687,32 @@ ExecuteGrantStmt_Namespace(GrantStmt *stmt)
errmsg("schema \"%s\" does not exist", nspname)));
pg_namespace_tuple = (Form_pg_namespace) GETSTRUCT(tuple);
+ ownerId = pg_namespace_tuple->nspowner;
+ grantorId = select_grantor(ownerId);
+
if (stmt->is_grant
- && !pg_namespace_ownercheck(HeapTupleGetOid(tuple), GetUserId())
- && pg_namespace_aclcheck(HeapTupleGetOid(tuple), GetUserId(), ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
+ && !pg_namespace_ownercheck(HeapTupleGetOid(tuple), GetUserId())
+ && pg_namespace_aclcheck(HeapTupleGetOid(tuple), GetUserId(),
+ ACL_GRANT_OPTION_FOR(privileges)) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_NAMESPACE,
nspname);
/*
- * If there's no ACL, create a default using the
- * pg_namespace.nspowner field.
+ * If there's no ACL, substitute the proper default.
*/
aclDatum = SysCacheGetAttr(NAMESPACENAME, tuple,
Anum_pg_namespace_nspacl,
&isNull);
if (isNull)
- old_acl = acldefault(ACL_OBJECT_NAMESPACE,
- pg_namespace_tuple->nspowner);
+ old_acl = acldefault(ACL_OBJECT_NAMESPACE, ownerId);
else
/* get a detoasted copy of the ACL */
old_acl = DatumGetAclPCopy(aclDatum);
new_acl = merge_acl_with_grant(old_acl, stmt->is_grant,
- stmt->grantees, privileges,
stmt->grant_option, stmt->behavior,
- pg_namespace_tuple->nspowner);
+ stmt->grantees, privileges,
+ grantorId, ownerId);
/* finished building new ACL value, now insert it */
MemSet(values, 0, sizeof(values));
@@ -1032,7 +1081,7 @@ pg_class_aclcheck(Oid table_oid, AclId userid, AclMode mode)
&isNull);
if (isNull)
{
- /* No ACL, so build default ACL for rel */
+ /* No ACL, so build default ACL */
AclId ownerId;
ownerId = ((Form_pg_class) GETSTRUCT(tuple))->relowner;
--
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