Require the issuer of CREATE TYPE to own the functions mentioned in the

type definition.  Because use of a type's I/O conversion functions isn't
access-checked, CREATE TYPE amounts to granting public execute permissions
on the functions, and so allowing it to anybody means that someone could
theoretically gain access to a function he's not supposed to be able to
execute.  The parameter-type restrictions already enforced by CREATE TYPE
make it fairly unlikely that this oversight is meaningful in practice,
but still it seems like a good idea to plug the hole going forward.
Also, document the implicit grant just in case anybody gets the idea of
building I/O functions that might need security restrictions.

diff --git a/doc/src/sgml/ref/create_type.sgml b/doc/src/sgml/ref/create_type.sgml
index 1205605ca36ea18863dae4c855ade95a478bf46f..a39c244c6c7d524c2e5047b4ba32d3d63ca8978d 100644 (file)
--- a/doc/src/sgml/ref/create_type.sgml
+++ b/doc/src/sgml/ref/create_type.sgml
@@ -1,5 +1,5 @@
 
 
@@ -446,6 +446,17 @@ CREATE TYPE name (
    internally-created array type names.
   
 
+  
+   Because there are no restrictions on use of a data type once it's been
+   created, creating a base type is tantamount to granting public execute
+   permission on the functions mentioned in the type definition.  (The creator
+   of the type is therefore required to own these functions.)  This is usually
+   not an issue for the sorts of functions that are useful in a type
+   definition.  But you might want to think twice before designing a type
+   in a way that would require secret information to be used
+   while converting it to or from external form.
+  
+
   
    In PostgreSQL versions before 7.3, it
    was customary to avoid creating a shell type by replacing the

diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 389fe133a5825822a03cc421b2d5c5d107c70e47..143695252f4290a4f8a9742573c3c0d4b7182e24 100644 (file)
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.85 2005/11/22 18:17:09 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.86 2006/01/13 18:06:45 tgl Exp $
  *
  * DESCRIPTION
  *   The "DefineFoo" routines take the parse tree and pick out the
@@ -330,6 +330,30 @@ DefineType(List *names, List *parameters)
    if (analyzeName)
        analyzeOid = findTypeAnalyzeFunction(analyzeName, typoid);
 
+   /*
+    * Check permissions on functions.  We choose to require the creator/owner
+    * of a type to also own the underlying functions.  Since creating a type
+    * is tantamount to granting public execute access on the functions, the
+    * minimum sane check would be for execute-with-grant-option.  But we don't
+    * have a way to make the type go away if the grant option is revoked, so
+    * ownership seems better.
+    */
+   if (inputOid && !pg_proc_ownercheck(inputOid, GetUserId()))
+       aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
+                      NameListToString(inputName));
+   if (outputOid && !pg_proc_ownercheck(outputOid, GetUserId()))
+       aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
+                      NameListToString(outputName));
+   if (receiveOid && !pg_proc_ownercheck(receiveOid, GetUserId()))
+       aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
+                      NameListToString(receiveName));
+   if (sendOid && !pg_proc_ownercheck(sendOid, GetUserId()))
+       aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
+                      NameListToString(sendName));
+   if (analyzeOid && !pg_proc_ownercheck(analyzeOid, GetUserId()))
+       aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
+                      NameListToString(analyzeName));
+
    /*
     * now have TypeCreate do all the real work.
     */