From owner-freebsd-bugs@FreeBSD.ORG  Sat Sep  6 10:30:16 2003
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@hub.freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 3C70E16A4BF
	for <freebsd-bugs@hub.freebsd.org>;
	Sat,  6 Sep 2003 10:30:16 -0700 (PDT)
Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21])
	by mx1.FreeBSD.org (Postfix) with ESMTP id BB74D43F3F
	for <freebsd-bugs@hub.freebsd.org>;
	Sat,  6 Sep 2003 10:30:15 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1])
	by freefall.freebsd.org (8.12.9/8.12.9) with ESMTP id h86HUFUp084162
	for <freebsd-bugs@freefall.freebsd.org>;
	Sat, 6 Sep 2003 10:30:15 -0700 (PDT)
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.12.9/8.12.9/Submit) id h86HUFft084161;
	Sat, 6 Sep 2003 10:30:15 -0700 (PDT)
Date: Sat, 6 Sep 2003 10:30:15 -0700 (PDT)
Message-Id: <200309061730.h86HUFft084161@freefall.freebsd.org>
To: freebsd-bugs@FreeBSD.org
From: Jonathan Lennox <lennox@cs.columbia.edu>
Subject: Re: bin/56500: rpc.lockd needs to use reserved ports
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
Reply-To: Jonathan Lennox <lennox@cs.columbia.edu>
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 06 Sep 2003 17:30:16 -0000

The following reply was made to PR bin/56500; it has been noted by GNATS.

From: Jonathan Lennox <lennox@cs.columbia.edu>
To: FreeBSD-gnats-submit@FreeBSD.org, freebsd-bugs@FreeBSD.org
Cc:  
Subject: Re: bin/56500: rpc.lockd needs to use reserved ports
Date: Sat, 6 Sep 2003 13:28:13 -0400

 After a day or so of untangling how RPC code works, I've worked out a patch.
 
 I'm pretty sure that this patch regains root privileges for the absolute
 minimum amount of time necessary to bind to a reserved port.
 
 I've tested this, and it does (along with the patch in kern/56461) allow me
 to sucessfully lock files from a Linux server -- and thus to invoke movemail
 on my mailspool, and thus to read my mail on my FreeBSD machine, which was
 the whole motivation.
 
 --- usr.sbin/rpc.lockd/lock_proc.c.orig	Sat Sep  6 12:48:10 2003
 +++ usr.sbin/rpc.lockd/lock_proc.c	Sat Sep  6 13:18:08 2003
 @@ -197,6 +197,8 @@
  	const char *netid;
  	struct netconfig *nconf;
  	char host[NI_MAXHOST];
 +	uid_t old_euid;
 +	int clnt_fd;
  
  	gettimeofday(&time_now, NULL);
  
 @@ -270,6 +272,22 @@
  		syslog(LOG_ERR, "Unable to return result to %s", host);
  		return NULL;
  	}
 +
 +	/* Get the FD of the client, for bindresvport. */ 
 +	clnt_control(client, CLGET_FD, &clnt_fd);
 +
 +	/* Regain root privileges, for bindresvport. */
 +	old_euid = geteuid();
 +	seteuid(0);
 +
 +	/*
 +	 * Bind the client FD to a reserved port.
 +	 * Some NFS servers reject any NLM request from a non-reserved port. 
 +	 */ 
 +	bindresvport(clnt_fd, NULL);
 +
 +	/* Drop root privileges again. */
 +	seteuid(old_euid);
  
  	/* Success - update the cache entry */
  	clnt_cache_ptr[clnt_cache_next_to_use] = client;