Fix bug in SET SESSION AUTHORIZATION that allows unprivileged users to crash

the server, if it has been compiled with Asserts enabled (CVE-2006-0553).
Thanks to Akio Ishida for reporting this problem.

diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index ff814c3208f783abea2255e79bb73940572bbc38..87f8953ee2663ef169a63684a2b31044b83b8eb5 100644 (file)
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/variable.c,v 1.71.2.3 2005/06/05 01:49:06 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/variable.c,v 1.71.2.4 2006/02/12 22:33:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -532,6 +532,8 @@ show_server_encoding(void)
  * that can be re-used directly.  We store the string in the form of
  * NAMEDATALEN 'x's followed by the numeric userid --- this cannot conflict
  * with any valid user name, because of the NAMEDATALEN limit on names.
+ * (NOTE: we rely on guc.c to have properly truncated any incoming value,
+ * but not to truncate already-stored values.  See GUC_IS_NAME processing.)
  */
 const char *
 assign_session_authorization(const char *value, bool doit, bool interactive)

diff --git a/src/backend/utils/mb/encnames.c b/src/backend/utils/mb/encnames.c
index c74808b2c0242412e03523835b6d05f7373c97e8..6dd0e6e638a5ea9f7abd249d2bf76d6d60e5dcd6 100644 (file)
--- a/src/backend/utils/mb/encnames.c
+++ b/src/backend/utils/mb/encnames.c
@@ -2,7 +2,7 @@
  * Encoding names and routines for work with it. All
  * in this file is shared bedween FE and BE.
  *
- * $Id: encnames.c,v 1.10.2.1 2002/12/09 17:45:17 momjian Exp $
+ * $Id: encnames.c,v 1.10.2.2 2006/02/12 22:33:47 tgl Exp $
  */
 #ifdef FRONTEND
 #include "postgres_fe.h"
@@ -436,7 +436,7 @@ pg_char_to_encname_struct(const char *name)
    if (name == NULL || *name == '\0')
        return NULL;
 
-   if (strlen(name) > NAMEDATALEN)
+   if (strlen(name) >= NAMEDATALEN)
    {
 #ifdef FRONTEND
        fprintf(stderr, "pg_char_to_encname_struct(): encoding name too long");

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index b49b36565e604f06714e8977f2e431e5843b61cc..af64f0ad34f7ad0df8c072610ca298b3d4b66961 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -5,7 +5,7 @@
  * command, configuration file, and command line options.
  * See src/backend/utils/misc/README for more information.
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.99.2.5 2003/04/04 00:32:57 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.99.2.6 2006/02/12 22:33:47 tgl Exp $
  *
  * Copyright 2000 by PostgreSQL Global Development Group
  * Written by Peter Eisentraut <peter_e@gmx.net>.
@@ -170,6 +170,7 @@ struct config_generic
 #define GUC_LIST_QUOTE     0x0002      /* double-quote list elements */
 #define GUC_NO_SHOW_ALL        0x0004      /* exclude from SHOW ALL */
 #define GUC_NO_RESET_ALL   0x0008      /* exclude from RESET ALL */
+#define GUC_IS_NAME            0x0010      /* limit string to NAMEDATALEN-1 */
 
 /* bit values in status field */
 #define GUC_HAVE_TENTATIVE 0x0001      /* tentative value is defined */
@@ -736,7 +737,7 @@ static struct config_string
            ConfigureNamesString[] =
 {
    {
-       {"client_encoding", PGC_USERSET}, &client_encoding_string,
+       {"client_encoding", PGC_USERSET, GUC_IS_NAME}, &client_encoding_string,
        "SQL_ASCII", assign_client_encoding, NULL
    },
 
@@ -799,7 +800,7 @@ static struct config_string
    },
 
    {
-       {"server_encoding", PGC_USERSET}, &server_encoding_string,
+       {"server_encoding", PGC_USERSET, GUC_IS_NAME}, &server_encoding_string,
        "SQL_ASCII", assign_server_encoding, show_server_encoding
    },
 
@@ -809,7 +810,7 @@ static struct config_string
    },
 
    {
-       {"session_authorization", PGC_USERSET, GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL},
+       {"session_authorization", PGC_USERSET, GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL},
        &session_authorization_string,
        NULL, assign_session_authorization, show_session_authorization
    },
@@ -1907,6 +1908,18 @@ set_config_option(const char *name, const char *value,
                        elog(elevel, "out of memory");
                        return false;
                    }
+                   /*
+                    * The only sort of "parsing" check we need to do is
+                    * apply truncation if GUC_IS_NAME.
+                    */
+                   if (conf->gen.flags & GUC_IS_NAME)
+                   {
+                       int len;
+
+                       len = pg_mbcliplen(newval, strlen(newval),
+                                          NAMEDATALEN-1);
+                       newval[len] = '\0';
+                   }
                }
                else if (conf->reset_val)
                {