From mboxrd@z Thu Jan  1 00:00:00 1970
From: Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] proc: make proc_fd_permission() thread-friendly
Date: Mon, 26 Aug 2013 11:09:25 -0700
Message-ID: <CA+55aFzCghYYF1_dcvBY9XZ82TU9b=hhgFqkGoWpaZuKJ7R6_A@mail.gmail.com>
References: <20130822201530.GL31117@1wt.eu>
	<20130824182939.GA23630@redhat.com>
	<20130824212432.GA9299@1wt.eu>
	<20130825052317.GZ27005@ZenIV.linux.org.uk>
	<20130825065039.GB9299@1wt.eu>
	<CA+55aFwFeCRcwn4qo570Y15mKrN3jEdN757PcZhrXs7QYi8MYA@mail.gmail.com>
	<20130825194844.GA16717@redhat.com>
	<CA+55aFzbY3zYD1i5x02Z-6K3nHKzJj6227ZBYRLqij9y0eXRqQ@mail.gmail.com>
	<20130826153301.GA15890@redhat.com>
	<20130826163704.GA21763@redhat.com>
	<20130826175441.GA28856@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Willy Tarreau <w@1wt.eu>, Al Viro <viro@zeniv.linux.org.uk>,
	Andy Lutomirski <luto@amacapital.net>,
	Ingo Molnar <mingo@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>,
	Brad Spengler <spender@grsecurity.net>,
	"Eric W. Biederman" <ebiederm@xmission.com>
To: Oleg Nesterov <oleg@redhat.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20130826175441.GA28856@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

On Mon, Aug 26, 2013 at 10:54 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> proc_fd_permission() says "process can still access /proc/self/fd
> after it has executed a setuid()", but the "task_pid() = proc_pid()
> check only helps if the task is group leader, /proc/self points to
> /proc/leader-pid.

Patch looks ok to me, but since this has never worked and nobody has
actually complained, I can't really convince myself that this is
critical.

So I'm not going to apply it for 3.11, and it had better wait for the
next merge window.

                 Linus