Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763927Ab3DDHvc (ORCPT ); Thu, 4 Apr 2013 03:51:32 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:10180 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763751Ab3DDHva (ORCPT ); Thu, 4 Apr 2013 03:51:30 -0400 Message-ID: <515D30F6.9010004@huawei.com> Date: Thu, 4 Apr 2013 15:51:18 +0800 From: dingtianhong User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 MIME-Version: 1.0 To: "Eric W. Biederman" CC: "David S. Miller" , Sven Joachim , Greg Kroah-Hartman , , , Eric Dumazet , Andy Lutomirski , Karel Srot , , Eric Dumazet Subject: Re: [PATCH 1/2] Revert "af_unix: dont send SCM_CREDENTIAL when dest socket is NULL" References: <20130402221104.163133110@linuxfoundation.org> <20130402221116.307254752@linuxfoundation.org> <87vc833kpf.fsf@turtle.gmx.de> <87k3ojnosa.fsf@xmission.com> <1365034777.13853.46.camel@edumazet-glaptop> <1365035424.13853.48.camel@edumazet-glaptop> <878v4zjei0.fsf@xmission.com> <87li8zhwkw.fsf_-_@xmission.com> In-Reply-To: <87li8zhwkw.fsf_-_@xmission.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.72.199] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1937 Lines: 51 On 2013/4/4 10:13, Eric W. Biederman wrote: > > This reverts commit 14134f6584212d585b310ce95428014b653dfaf6. > > The problem that the above patch was meant to address is that af_unix > messages are not being coallesced because we are sending unnecesarry > credentials. Not sending credentials in maybe_add_creds totally > breaks unconnected unix domain sockets that wish to send credentails > to other sockets. > thanks for check the question and make a fix solution, but I still doubt that if unconnected unix domain socket wish to send credentails to oher sockets, why dont set SOCK_PASSCRED on sock->flags, I think the user need to decide the param and shouldnt send creds by default way. Ding > In practice this break some versions of udev because they receive a > message and the sending uid is bogus so they drop the message. > > Cc: stable@vger.kernel.org > Reported-by: Sven Joachim > Signed-off-by: "Eric W. Biederman" > --- > net/unix/af_unix.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index 971282b..f153a8d 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -1412,8 +1412,8 @@ static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, > if (UNIXCB(skb).cred) > return; > if (test_bit(SOCK_PASSCRED, &sock->flags) || > - (other->sk_socket && > - test_bit(SOCK_PASSCRED, &other->sk_socket->flags))) { > + !other->sk_socket || > + test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { > UNIXCB(skb).pid = get_pid(task_tgid(current)); > UNIXCB(skb).cred = get_current_cred(); > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/