From owner-svn-src-all@FreeBSD.ORG  Thu Sep  4 01:21:33 2014
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id DFD2A6BC;
 Thu,  4 Sep 2014 01:21:33 +0000 (UTC)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id CBD4A13CD;
 Thu,  4 Sep 2014 01:21:33 +0000 (UTC)
Received: from svn.freebsd.org ([127.0.1.70])
 by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id s841LXMS088087;
 Thu, 4 Sep 2014 01:21:33 GMT (envelope-from mjg@FreeBSD.org)
Received: (from mjg@localhost)
 by svn.freebsd.org (8.14.9/8.14.9/Submit) id s841LXRq088086;
 Thu, 4 Sep 2014 01:21:33 GMT (envelope-from mjg@FreeBSD.org)
Message-Id: <201409040121.s841LXRq088086@svn.freebsd.org>
X-Authentication-Warning: svn.freebsd.org: mjg set sender to mjg@FreeBSD.org
 using -f
From: Mateusz Guzik <mjg@FreeBSD.org>
Date: Thu, 4 Sep 2014 01:21:33 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r271074 - head/sys/kern
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 04 Sep 2014 01:21:34 -0000

Author: mjg
Date: Thu Sep  4 01:21:33 2014
New Revision: 271074
URL: http://svnweb.freebsd.org/changeset/base/271074

Log:
  Plug a hypothetical use after free in sysctl kern.proc.groups.
  
  MFC after:	1 week

Modified:
  head/sys/kern/kern_proc.c

Modified: head/sys/kern/kern_proc.c
==============================================================================
--- head/sys/kern/kern_proc.c	Thu Sep  4 01:04:37 2014	(r271073)
+++ head/sys/kern/kern_proc.c	Thu Sep  4 01:21:33 2014	(r271074)
@@ -2508,6 +2508,7 @@ sysctl_kern_proc_groups(SYSCTL_HANDLER_A
 		return (EINVAL);
 	if (*pidp == -1) {	/* -1 means this process */
 		p = req->td->td_proc;
+		PROC_LOCK(p);
 	} else {
 		error = pget(*pidp, PGET_CANSEE, &p);
 		if (error != 0)
@@ -2515,8 +2516,7 @@ sysctl_kern_proc_groups(SYSCTL_HANDLER_A
 	}
 
 	cred = crhold(p->p_ucred);
-	if (*pidp != -1)
-		PROC_UNLOCK(p);
+	PROC_UNLOCK(p);
 
 	error = SYSCTL_OUT(req, cred->cr_groups,
 	    cred->cr_ngroups * sizeof(gid_t));