From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760681Ab2BJWxZ (ORCPT ); Fri, 10 Feb 2012 17:53:25 -0500 Received: from mail-pz0-f46.google.com ([209.85.210.46]:53942 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933234Ab2BJWuP (ORCPT ); Fri, 10 Feb 2012 17:50:15 -0500 MIME-Version: 1.0 Message-Id: <20120210224852.571157423@clark.kroah.org> User-Agent: quilt/0.51-15.1 Date: Fri, 10 Feb 2012 14:47:59 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Anton Blanchard , Eric Dumazet , "David S. Miller" , =?UTF-8?q?=E5=8D=95=E5=8D=AB?= Subject: [20/21] net: fix sk_forward_alloc corruptions In-Reply-To: <20120210224858.GA30752@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 2903037400a26e7c0cc93ab75a7d62abfacdf485 upstream. As David found out, sock_queue_err_skb() should be called with socket lock hold, or we risk sk_forward_alloc corruption, since we use non atomic operations to update this field. This patch adds bh_lock_sock()/bh_unlock_sock() pair to three spots. (BH already disabled) 1) skb_tstamp_tx() 2) Before calling ip_icmp_error(), in __udp4_lib_err() 3) Before calling ipv6_icmp_error(), in __udp6_lib_err() Reported-by: Anton Blanchard Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Cc: 单卫 Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 4 ++++ net/ipv4/udp.c | 2 ++ net/ipv6/udp.c | 6 ++++-- 3 files changed, 10 insertions(+), 2 deletions(-) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3008,7 +3008,11 @@ void skb_tstamp_tx(struct sk_buff *orig_ memset(serr, 0, sizeof(*serr)); serr->ee.ee_errno = ENOMSG; serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; + + bh_lock_sock(sk); err = sock_queue_err_skb(sk, skb); + bh_unlock_sock(sk); + if (err) kfree_skb(skb); } --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -441,7 +441,9 @@ void __udp4_lib_err(struct sk_buff *skb, if (!harderr || sk->sk_state != TCP_ESTABLISHED) goto out; } else { + bh_lock_sock(sk); ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); + bh_unlock_sock(sk); } sk->sk_err = err; sk->sk_error_report(sk); --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -337,9 +337,11 @@ void __udp6_lib_err(struct sk_buff *skb, if (sk->sk_state != TCP_ESTABLISHED && !np->recverr) goto out; - if (np->recverr) + if (np->recverr) { + bh_lock_sock(sk); ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); - + bh_unlock_sock(sk); + } sk->sk_err = err; sk->sk_error_report(sk); out: