From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753270Ab2EBN2r (ORCPT ); Wed, 2 May 2012 09:28:47 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:49886 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127Ab2EBN2q (ORCPT ); Wed, 2 May 2012 09:28:46 -0400 Subject: Re: [PATCH] net: l2tp: unlock socket lock before returning from l2tp_ip_sendmsg From: Eric Dumazet To: Sasha Levin Cc: davem@davemloft.net, jchapman@katalix.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, davej@redhat.com In-Reply-To: <1335964237-1139-1-git-send-email-levinsasha928@gmail.com> References: <1335964237-1139-1-git-send-email-levinsasha928@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 02 May 2012 15:28:38 +0200 Message-ID: <1335965318.22133.568.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2012-05-02 at 15:10 +0200, Sasha Levin wrote: > l2tp_ip_sendmsg could return without releasing socket lock, making it all the > way to userspace, and generating the following warning: > > [ 130.891594] ================================================ > [ 130.894569] [ BUG: lock held when returning to user space! ] > [ 130.897257] 3.4.0-rc5-next-20120501-sasha #104 Tainted: G W > [ 130.900336] ------------------------------------------------ > [ 130.902996] trinity/8384 is leaving the kernel with locks still held! > [ 130.906106] 1 lock held by trinity/8384: > [ 130.907924] #0: (sk_lock-AF_INET){+.+.+.}, at: [] l2tp_ip_sendmsg+0x2f/0x550 > > Signed-off-by: Sasha Levin > --- > net/l2tp/l2tp_ip.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c > index 585d93e..a4d8364 100644 > --- a/net/l2tp/l2tp_ip.c > +++ b/net/l2tp/l2tp_ip.c > @@ -442,8 +442,10 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m > > daddr = lip->l2tp_addr.s_addr; > } else { > - if (sk->sk_state != TCP_ESTABLISHED) > - return -EDESTADDRREQ; > + if (sk->sk_state != TCP_ESTABLISHED) { > + rc = -EDESTADDRREQ; > + goto out; > + } > > daddr = inet->inet_daddr; > connected = 1; Good catch, but please use existing code style in this function. rc = -EDESTADDRREQ; if (sk->sk_state != TCP_ESTABLISHED) goto out; Also, please add in your commit message bug origin to ease stable team work (not counting reviewers work) Bug added in commit 2f16270f41e1 (l2tp: Fix locking in l2tp_ip.c) Really, given the amount of patches you already sent, you should already know that. Thanks