From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761910AbZD2W0v (ORCPT ); Wed, 29 Apr 2009 18:26:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758233AbZD2WVX (ORCPT ); Wed, 29 Apr 2009 18:21:23 -0400 Received: from kroah.org ([198.145.64.141]:40325 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758390AbZD2WVS (ORCPT ); Wed, 29 Apr 2009 18:21:18 -0400 X-Mailbox-Line: From gregkh@mini.kroah.org Wed Apr 29 15:09:25 2009 Message-Id: <20090429220925.111124389@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Wed, 29 Apr 2009 15:07:14 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jesper Nilsson , "David S. Miller" Subject: [patch 15/58] ipv6: Plug sk_buff leak in ipv6_rcv (net/ipv6/ip6_input.c) References: <20090429220659.339950874@mini.kroah.org> Content-Disposition: inline; filename=ipv6-plug-sk_buff-leak-in-ipv6_rcv.patch In-Reply-To: <20090429221657.GA11765@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jesper Nilsson [ Upstream commit 71f6f6dfdf7c7a67462386d9ea05c1095a89c555 ] Commit 778d80be52699596bf70e0eb0761cf5e1e46088d (ipv6: Add disable_ipv6 sysctl to disable IPv6 operaion on specific interface) seems to have introduced a leak of sk_buff's for ipv6 traffic, at least in some configurations where idev is NULL, or when ipv6 is disabled via sysctl. The problem is that if the first condition of the if-statement returns non-NULL, it returns an skb with only one reference, and when the other conditions apply, execution jumps to the "out" label, which does not call kfree_skb for it. To plug this leak, change to use the "drop" label instead. (this relies on it being ok to call kfree_skb on NULL) This also allows us to avoid calling rcu_read_unlock here, and removes the only user of the "out" label. Signed-off-by: Jesper Nilsson Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_input.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -74,8 +74,7 @@ int ipv6_rcv(struct sk_buff *skb, struct if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL || !idev || unlikely(idev->cnf.disable_ipv6)) { IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS); - rcu_read_unlock(); - goto out; + goto drop; } memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); @@ -145,7 +144,6 @@ err: drop: rcu_read_unlock(); kfree_skb(skb); -out: return 0; }