The original patch to disallow non-passworded connections to non-superusers

failed to cover all the ways in which a connection can be initiated in dblink.
Plug the remaining holes.  Also, disallow transient connections in functions
for which that feature makes no sense (because they are only sensible as
part of a sequence of operations on the same connection).  Joe Conway

Security: CVE-2007-6601

diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index 676dc7856e059bb100675f90c89319c85fb02988..b95795a2b1ef476f5e66583182c1b7e5f4ea6865 100644 (file)
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -8,7 +8,7 @@
  * Darko Prenosil <Darko.Prenosil@finteh.hr>
  * Shridhar Daithankar <shridhar_daithankar@persistent.co.in>
  *
- * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.60.2.1 2007/07/09 01:32:30 joe Exp $
+ * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.60.2.2 2008/01/03 21:28:18 tgl Exp $
  * Copyright (c) 2001-2006, PostgreSQL Global Development Group
  * ALL RIGHTS RESERVED;
  *
@@ -91,6 +91,7 @@ static HeapTuple get_tuple_of_interest(Oid relid, int2vector *pkattnums, int16 p
 static Oid     get_relid_from_relname(text *relname_text);
 static char *generate_relation_name(Oid relid);
 static char *connstr_strip_password(const char *connstr);
+static void dblink_security_check(PGconn *conn, remoteConn *rconn, const char *connstr);
 
 /* Global */
 static remoteConn *pconn = NULL;
@@ -177,6 +178,7 @@ typedef struct remoteConnHashEnt
                        else \
                        { \
                                connstr = conname_or_str; \
+                               dblink_security_check(conn, rconn, connstr); \
                                conn = PQconnectdb(connstr); \
                                if (PQstatus(conn) == CONNECTION_BAD) \
                                { \
@@ -191,6 +193,16 @@ typedef struct remoteConnHashEnt
                        } \
        } while (0)
 
+#define DBLINK_GET_NAMED_CONN \
+       do { \
+                       char *conname = GET_STR(PG_GETARG_TEXT_P(0)); \
+                       rconn = getConnectionByName(conname); \
+                       if(rconn) \
+                               conn = rconn->conn; \
+                       else \
+                               DBLINK_CONN_NOT_AVAIL; \
+       } while (0)
+
 #define DBLINK_INIT \
        do { \
                        if (!pconn) \
@@ -231,27 +243,8 @@ dblink_connect(PG_FUNCTION_ARGS)
        if (connname)
                rconn = (remoteConn *) palloc(sizeof(remoteConn));
 
-       /* for non-superusers, check that server requires a password */
-       if (!superuser())
-       {
-               /* this attempt must fail */
-               conn = PQconnectdb(connstr_strip_password(connstr));
-
-               if (PQstatus(conn) == CONNECTION_OK)
-               {
-                       PQfinish(conn);
-                       if (rconn)
-                               pfree(rconn);
-
-                       ereport(ERROR,
-                                       (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
-                                        errmsg("password is required"),
-                                        errdetail("Non-superuser cannot connect if the server does not request a password."),
-                                        errhint("Target server's authentication method must be changed.")));
-               }
-               else
-                       PQfinish(conn);
-       }
+       /* check password used if not superuser */
+       dblink_security_check(conn, rconn, connstr);
        conn = PQconnectdb(connstr);
 
        MemoryContextSwitchTo(oldcontext);
@@ -1053,17 +1046,11 @@ PG_FUNCTION_INFO_V1(dblink_is_busy);
 Datum
 dblink_is_busy(PG_FUNCTION_ARGS)
 {
-       char       *msg;
        PGconn     *conn = NULL;
-       char       *conname = NULL;
-       char       *connstr = NULL;
        remoteConn *rconn = NULL;
-       bool            freeconn = false;
 
        DBLINK_INIT;
-       DBLINK_GET_CONN;
-       if (!conn)
-               DBLINK_CONN_NOT_AVAIL;
+       DBLINK_GET_NAMED_CONN;
 
        PQconsumeInput(conn);
        PG_RETURN_INT32(PQisBusy(conn));
@@ -1084,26 +1071,20 @@ PG_FUNCTION_INFO_V1(dblink_cancel_query);
 Datum
 dblink_cancel_query(PG_FUNCTION_ARGS)
 {
-       char       *msg;
        int                     res = 0;
        PGconn     *conn = NULL;
-       char       *conname = NULL;
-       char       *connstr = NULL;
        remoteConn *rconn = NULL;
-       bool            freeconn = false;
        PGcancel   *cancel;
        char            errbuf[256];
 
        DBLINK_INIT;
-       DBLINK_GET_CONN;
-       if (!conn)
-               DBLINK_CONN_NOT_AVAIL;
+       DBLINK_GET_NAMED_CONN;
        cancel = PQgetCancel(conn);
 
        res = PQcancel(cancel, errbuf, 256);
        PQfreeCancel(cancel);
 
-       if (res == 0)
+       if (res == 1)
                PG_RETURN_TEXT_P(GET_TEXT("OK"));
        else
                PG_RETURN_TEXT_P(GET_TEXT(errbuf));
@@ -1126,18 +1107,13 @@ dblink_error_message(PG_FUNCTION_ARGS)
 {
        char       *msg;
        PGconn     *conn = NULL;
-       char       *conname = NULL;
-       char       *connstr = NULL;
        remoteConn *rconn = NULL;
-       bool            freeconn = false;
 
        DBLINK_INIT;
-       DBLINK_GET_CONN;
-       if (!conn)
-               DBLINK_CONN_NOT_AVAIL;
+       DBLINK_GET_NAMED_CONN;
 
        msg = PQerrorMessage(conn);
-       if (!msg)
+       if (msg == NULL || msg[0] == '\0')
                PG_RETURN_TEXT_P(GET_TEXT("OK"));
        else
                PG_RETURN_TEXT_P(GET_TEXT(msg));
@@ -2428,3 +2404,28 @@ connstr_strip_password(const char *connstr)
 
        return result.data;
 }
+
+static void
+dblink_security_check(PGconn *conn, remoteConn *rconn, const char *connstr)
+{
+       if (!superuser())
+       {
+               /* this attempt must fail */
+               conn = PQconnectdb(connstr_strip_password(connstr));
+
+               if (PQstatus(conn) == CONNECTION_OK)
+               {
+                       PQfinish(conn);
+                       if (rconn)
+                               pfree(rconn);
+
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
+                                        errmsg("password is required"),
+                                        errdetail("Non-superuser cannot connect if the server does not request a password."),
+                                        errhint("Target server's authentication method must be changed.")));
+               }
+               else
+                       PQfinish(conn);
+       }
+}

diff --git a/contrib/dblink/expected/dblink.out b/contrib/dblink/expected/dblink.out
index c98ae5cf6b55e8dc50466e7135bf1f8e003db36d..67c7194e93ba4c52fa8ba1450a5afdc4581491cf 100644 (file)
--- a/contrib/dblink/expected/dblink.out
+++ b/contrib/dblink/expected/dblink.out
@@ -722,6 +722,12 @@ SELECT dblink_get_connections();
  {dtest1,dtest2,dtest3}
 (1 row)
 
+SELECT dblink_is_busy('dtest1');
+ dblink_is_busy 
+----------------
+              0
+(1 row)
+
 SELECT dblink_disconnect('dtest1');
  dblink_disconnect 
 -------------------
@@ -756,3 +762,34 @@ SELECT * from result;
  10 | k  | {a10,b10,c10}
 (11 rows)
 
+SELECT dblink_connect('dtest1', 'dbname=contrib_regression');
+ dblink_connect 
+----------------
+ OK
+(1 row)
+
+SELECT * from 
+ dblink_send_query('dtest1', 'select * from foo where f1 < 3') as t1;
+ t1 
+----
+  1
+(1 row)
+
+SELECT dblink_cancel_query('dtest1');
+ dblink_cancel_query 
+---------------------
+ OK
+(1 row)
+
+SELECT dblink_error_message('dtest1');
+ dblink_error_message 
+----------------------
+ OK
+(1 row)
+
+SELECT dblink_disconnect('dtest1');
+ dblink_disconnect 
+-------------------
+ OK
+(1 row)
+

diff --git a/contrib/dblink/sql/dblink.sql b/contrib/dblink/sql/dblink.sql
index 52a3d049b9c2db92318547d14480cec938330c32..c2d093323ab63de4c72579d0060c5a2d8ac145a6 100644 (file)
--- a/contrib/dblink/sql/dblink.sql
+++ b/contrib/dblink/sql/dblink.sql
@@ -342,9 +342,18 @@ UNION
 ORDER by f1;
 
 SELECT dblink_get_connections();
+SELECT dblink_is_busy('dtest1');
 
 SELECT dblink_disconnect('dtest1');
 SELECT dblink_disconnect('dtest2');
 SELECT dblink_disconnect('dtest3');
+
 SELECT * from result;
 
+SELECT dblink_connect('dtest1', 'dbname=contrib_regression');
+SELECT * from 
+ dblink_send_query('dtest1', 'select * from foo where f1 < 3') as t1;
+
+SELECT dblink_cancel_query('dtest1');
+SELECT dblink_error_message('dtest1');
+SELECT dblink_disconnect('dtest1');