From patchwork Wed Jan 27 00:14:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 573706 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 2F9D01402C9; Wed, 27 Jan 2016 11:21:01 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1aODr0-0005i9-27; Wed, 27 Jan 2016 00:20:58 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1aODkX-0002In-9F for kernel-team@lists.ubuntu.com; Wed, 27 Jan 2016 00:14:17 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1aODkW-0007qK-Sh; Wed, 27 Jan 2016 00:14:17 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1aODkU-000689-4f; Tue, 26 Jan 2016 16:14:14 -0800 From: Kamal Mostafa To: Eric Dumazet Subject: [4.2.y-ckt stable] Patch "ipv6: tcp: add rcu locking in tcp_v6_send_synack()" has been added to the 4.2.y-ckt tree Date: Tue, 26 Jan 2016 16:14:13 -0800 Message-Id: <1453853653-23535-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 X-Extended-Stable: 4.2 Cc: Dave Jones , Kamal Mostafa , "David S. Miller" , kernel-team@lists.ubuntu.com X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled ipv6: tcp: add rcu locking in tcp_v6_send_synack() to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt3. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 1df437a342b11b92c0c761d099fb84409fc033ad Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 8 Jan 2016 09:35:51 -0800 Subject: ipv6: tcp: add rcu locking in tcp_v6_send_synack() commit 3e4006f0b86a5ae5eb0e8215f9a9e1db24506977 upstream. When first SYNACK is sent, we already hold rcu_read_lock(), but this is not true if a SYNACK is retransmitted, as a timer (soft) interrupt does not hold rcu_read_lock() Fixes: 45f6fad84cc30 ("ipv6: add complete rcu protection around np->opt") Reported-by: Dave Jones Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/ipv6/tcp_ipv6.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.9.1 diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 682756c..8a51c16 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -462,8 +462,10 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst, fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); skb_set_queue_mapping(skb, queue_mapping); + rcu_read_lock(); err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass); + rcu_read_unlock(); err = net_xmit_eval(err); }