From patchwork Mon Jan 4 17:31:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 562503 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 486791402A8; Tue, 5 Jan 2016 04:32:23 +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 1aG8zR-00052y-KL; Mon, 04 Jan 2016 17:32:17 +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 1aG8yd-0004j1-Ph for kernel-team@lists.ubuntu.com; Mon, 04 Jan 2016 17:31:27 +0000 Received: from 1.general.henrix.uk.vpn ([10.172.192.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1aG8yd-00026c-4X; Mon, 04 Jan 2016 17:31:27 +0000 From: Luis Henriques To: Eric Dumazet Subject: [3.16.y-ckt stable] Patch "tcp: md5: fix lockdep annotation" has been added to staging queue Date: Mon, 4 Jan 2016 17:31:25 +0000 Message-Id: <1451928685-956-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Cc: Willem de Bruijn , "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 tcp: md5: fix lockdep annotation to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt22. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From d230c3a0df19ac1c3e5353ad477f9e59934ae77c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 18 Nov 2015 12:40:13 -0800 Subject: tcp: md5: fix lockdep annotation commit 1b8e6a01e19f001e9f93b39c32387961c91ed3cc upstream. When a passive TCP is created, we eventually call tcp_md5_do_add() with sk pointing to the child. It is not owner by the user yet (we will add this socket into listener accept queue a bit later anyway) But we do own the spinlock, so amend the lockdep annotation to avoid following splat : [ 8451.090932] net/ipv4/tcp_ipv4.c:923 suspicious rcu_dereference_protected() usage! [ 8451.090932] [ 8451.090932] other info that might help us debug this: [ 8451.090932] [ 8451.090934] [ 8451.090934] rcu_scheduler_active = 1, debug_locks = 1 [ 8451.090936] 3 locks held by socket_sockopt_/214795: [ 8451.090936] #0: (rcu_read_lock){.+.+..}, at: [] __netif_receive_skb_core+0x151/0xe90 [ 8451.090947] #1: (rcu_read_lock){.+.+..}, at: [] ip_local_deliver_finish+0x43/0x2b0 [ 8451.090952] #2: (slock-AF_INET){+.-...}, at: [] sk_clone_lock+0x1c5/0x500 [ 8451.090958] [ 8451.090958] stack backtrace: [ 8451.090960] CPU: 7 PID: 214795 Comm: socket_sockopt_ [ 8451.091215] Call Trace: [ 8451.091216] [] dump_stack+0x55/0x76 [ 8451.091229] [] lockdep_rcu_suspicious+0xeb/0x110 [ 8451.091235] [] tcp_md5_do_add+0x1bf/0x1e0 [ 8451.091239] [] tcp_v4_syn_recv_sock+0x1f1/0x4c0 [ 8451.091242] [] ? tcp_v4_md5_hash_skb+0x167/0x190 [ 8451.091246] [] tcp_check_req+0x3c8/0x500 [ 8451.091249] [] ? tcp_v4_inbound_md5_hash+0x11e/0x190 [ 8451.091253] [] tcp_v4_rcv+0x3c0/0x9f0 [ 8451.091256] [] ? ip_local_deliver_finish+0x43/0x2b0 [ 8451.091260] [] ip_local_deliver_finish+0xb6/0x2b0 [ 8451.091263] [] ? ip_local_deliver_finish+0x43/0x2b0 [ 8451.091267] [] ip_local_deliver+0x48/0x80 [ 8451.091270] [] ip_rcv_finish+0x160/0x700 [ 8451.091273] [] ip_rcv+0x29e/0x3d0 [ 8451.091277] [] __netif_receive_skb_core+0xb47/0xe90 Fixes: a8afca0329988 ("tcp: md5: protects md5sig_info with RCU") Signed-off-by: Eric Dumazet Reported-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- net/ipv4/tcp_ipv4.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index b68fd0d65411..0fd3c84ffaf8 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -992,7 +992,8 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, } md5sig = rcu_dereference_protected(tp->md5sig_info, - sock_owned_by_user(sk)); + sock_owned_by_user(sk) || + lockdep_is_held(&sk->sk_lock.slock)); if (!md5sig) { md5sig = kmalloc(sizeof(*md5sig), gfp); if (!md5sig)