From 58c7bef91386eba1ebb766413f33d4fe90b0948a Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 3 Jan 2008 21:28:18 +0000 Subject: [PATCH] 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 --- contrib/dblink/dblink.c | 89 +++++++++++++++--------------- contrib/dblink/expected/dblink.out | 37 +++++++++++++ contrib/dblink/sql/dblink.sql | 9 +++ 3 files changed, 91 insertions(+), 44 deletions(-) diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c index 676dc7856e..b95795a2b1 100644 --- a/contrib/dblink/dblink.c +++ b/contrib/dblink/dblink.c @@ -8,7 +8,7 @@ * Darko Prenosil * Shridhar Daithankar * - * $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 c98ae5cf6b..67c7194e93 100644 --- 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 52a3d049b9..c2d093323a 100644 --- 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');