From owner-svn-src-head@FreeBSD.ORG  Sat Dec  8 09:48:04 2012
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id 15EF27E2;
 Sat,  8 Dec 2012 09:48:04 +0000 (UTC)
 (envelope-from adrian@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 by mx1.freebsd.org (Postfix) with ESMTP id EE13C8FC12;
 Sat,  8 Dec 2012 09:48:03 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
 by svn.freebsd.org (8.14.5/8.14.5) with ESMTP id qB89m39E013283;
 Sat, 8 Dec 2012 09:48:03 GMT (envelope-from adrian@svn.freebsd.org)
Received: (from adrian@localhost)
 by svn.freebsd.org (8.14.5/8.14.5/Submit) id qB89m3fi013282;
 Sat, 8 Dec 2012 09:48:03 GMT (envelope-from adrian@svn.freebsd.org)
Message-Id: <201212080948.qB89m3fi013282@svn.freebsd.org>
From: Adrian Chadd <adrian@FreeBSD.org>
Date: Sat, 8 Dec 2012 09:48:03 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r244025 - head/sys/net80211
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 08 Dec 2012 09:48:04 -0000

Author: adrian
Date: Sat Dec  8 09:48:03 2012
New Revision: 244025
URL: http://svnweb.freebsd.org/changeset/base/244025

Log:
  Fix a use-after-free bug in the Atheros fast-frames support.
  
  Tested:
  
  * AR5212 AP, AR5413 STA, iperf TCP STA->AP, destroyed and/or shutdown
    the STA vap during active iperf TCP traffic.
  
  PR:		kern/174273
  MFC after:	1 week

Modified:
  head/sys/net80211/ieee80211_superg.c

Modified: head/sys/net80211/ieee80211_superg.c
==============================================================================
--- head/sys/net80211/ieee80211_superg.c	Sat Dec  8 09:23:05 2012	(r244024)
+++ head/sys/net80211/ieee80211_superg.c	Sat Dec  8 09:48:03 2012	(r244025)
@@ -784,7 +784,7 @@ ieee80211_ff_node_cleanup(struct ieee802
 	struct ieee80211com *ic = ni->ni_ic;
 	struct ieee80211_superg *sg = ic->ic_superg;
 	struct ieee80211_tx_ampdu *tap;
-	struct mbuf *m, *head;
+	struct mbuf *m, *next_m, *head;
 	int tid;
 
 	IEEE80211_LOCK(ic);
@@ -803,9 +803,16 @@ ieee80211_ff_node_cleanup(struct ieee802
 	}
 	IEEE80211_UNLOCK(ic);
 
-	for (m = head; m != NULL; m = m->m_nextpkt) {
+	/*
+	 * Free mbufs, taking care to not dereference the mbuf after
+	 * we free it (hence grabbing m_nextpkt before we free it.)
+	 */
+	m = head;
+	while (m != NULL) {
+		next_m = m->m_nextpkt;
 		m_freem(m);
 		ieee80211_free_node(ni);
+		m = next_m;
 	}
 }