From owner-svn-src-stable-11@freebsd.org  Fri Jan  6 03:54:27 2017
Return-Path: <owner-svn-src-stable-11@freebsd.org>
Delivered-To: svn-src-stable-11@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5EEE5CA07D1;
 Fri,  6 Jan 2017 03:54:27 +0000 (UTC)
 (envelope-from ngie@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::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 2E0B6151A;
 Fri,  6 Jan 2017 03:54:27 +0000 (UTC)
 (envelope-from ngie@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v063sQ06057399;
 Fri, 6 Jan 2017 03:54:26 GMT (envelope-from ngie@FreeBSD.org)
Received: (from ngie@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id v063sQgh057398;
 Fri, 6 Jan 2017 03:54:26 GMT (envelope-from ngie@FreeBSD.org)
Message-Id: <201701060354.v063sQgh057398@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: ngie set sender to
 ngie@FreeBSD.org using -f
From: Ngie Cooper <ngie@FreeBSD.org>
Date: Fri, 6 Jan 2017 03:54:26 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org
Subject: svn commit: r311467 - stable/11/contrib/bsnmp/snmp_mibII
X-SVN-Group: stable-11
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-stable-11@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: SVN commit messages for only the 11-stable src tree
 <svn-src-stable-11.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-stable-11>, 
 <mailto:svn-src-stable-11-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-stable-11/>
List-Post: <mailto:svn-src-stable-11@freebsd.org>
List-Help: <mailto:svn-src-stable-11-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-stable-11>, 
 <mailto:svn-src-stable-11-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 06 Jan 2017 03:54:27 -0000

Author: ngie
Date: Fri Jan  6 03:54:26 2017
New Revision: 311467
URL: https://svnweb.freebsd.org/changeset/base/311467

Log:
  MFC r310873:
  
  Guard against use-after-free after calling mibif_free(..)
  
  Set variables to NULL after calling free.
  
  Also, remove unnecessary if (x != NULL) checks before calling free(x)

Modified:
  stable/11/contrib/bsnmp/snmp_mibII/mibII.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/contrib/bsnmp/snmp_mibII/mibII.c
==============================================================================
--- stable/11/contrib/bsnmp/snmp_mibII/mibII.c	Fri Jan  6 03:53:44 2017	(r311466)
+++ stable/11/contrib/bsnmp/snmp_mibII/mibII.c	Fri Jan  6 03:54:26 2017	(r311467)
@@ -707,10 +707,11 @@ mibif_free(struct mibif *ifp)
 	}
 
 	free(ifp->private);
-	if (ifp->physaddr != NULL)
-		free(ifp->physaddr);
-	if (ifp->specmib != NULL)
-		free(ifp->specmib);
+	ifp->private = NULL;
+	free(ifp->physaddr);
+	ifp->physaddr = NULL;
+	free(ifp->specmib);
+	ifp->specmib = NULL;
 
 	STAILQ_FOREACH(map, &mibindexmap_list, link)
 		if (map->mibif == ifp) {
@@ -745,8 +746,8 @@ mibif_free(struct mibif *ifp)
 		at = at1;
 	}
 
-
 	free(ifp);
+	ifp = NULL;
 	mib_if_number--;
 	mib_iftable_last_change = this_tick;
 }