From: dingtianhong <dingtianhong@huawei•com>
To: "Eric W. Biederman" <ebiederm@xmission•com>
Cc: "David S. Miller" <davem@davemloft•net>,
Sven Joachim <svenjoac@gmx•de>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
<linux-kernel@vger•kernel.org>, <stable@vger•kernel.org>,
Eric Dumazet <edumazet@google•com>,
Andy Lutomirski <luto@amacapital•net>,
Karel Srot <ksrot@redhat•com>, <netdev@vger•kernel.org>,
Eric Dumazet <eric.dumazet@gmail•com>
Subject: Re: [PATCH 1/2] Revert "af_unix: dont send SCM_CREDENTIAL when dest socket is NULL"
Date: Thu, 4 Apr 2013 15:51:18 +0800 [thread overview]
Message-ID: <515D30F6.9010004@huawei.com> (raw)
In-Reply-To: <87li8zhwkw.fsf_-_@xmission.com>
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 <svenjoac@gmx•de>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission•com>
> ---
> 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();
> }
>
next prev parent reply other threads:[~2013-04-04 7:51 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20130402221104.163133110@linuxfoundation.org>
[not found] ` <20130402221116.307254752@linuxfoundation.org>
[not found] ` <87vc833kpf.fsf@turtle.gmx.de>
[not found] ` <87k3ojnosa.fsf@xmission.com>
[not found] ` <1365034777.13853.46.camel@edumazet-glaptop>
[not found] ` <1365035424.13853.48.camel@edumazet-glaptop>
[not found] ` <878v4zjei0.fsf@xmission.com>
2013-04-04 2:13 ` [PATCH 1/2] Revert "af_unix: dont send SCM_CREDENTIAL when dest socket is NULL" Eric W. Biederman
2013-04-04 2:14 ` [PATCH 2/2] af_unix: If we don't care about credentials coallesce all messages Eric W. Biederman
2013-04-04 3:28 ` [PATCH 3/2] scm: Stop passing struct cred Eric W. Biederman
2013-04-05 4:47 ` David Miller
2013-04-04 7:56 ` [PATCH 2/2] af_unix: If we don't care about credentials coallesce all messages dingtianhong
2013-04-04 10:36 ` Eric W. Biederman
2013-04-05 4:47 ` David Miller
2013-04-04 7:51 ` dingtianhong [this message]
2013-04-04 10:22 ` [PATCH 1/2] Revert "af_unix: dont send SCM_CREDENTIAL when dest socket is NULL" Eric W. Biederman
2013-04-05 4:47 ` David Miller
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