Re: [PATCH v2 2/3] seccomp: Introduce addfd ioctl to seccomp user notifier

From: Kees Cook <keescook@chromium.org>
To: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Sargun Dhillon <sargun@sargun.me>,
	containers@lists.linux-foundation.org, cyphar@cyphar.com,
	jannh@google.com, jeffv@google.com, linux-api@vger.kernel.org,
	linux-kernel@vger.kernel.org, palmer@google.com,
	rsesek@google.com, tycho@tycho.ws,
	Matt Denton <mpdenton@google.com>,
	Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH v2 2/3] seccomp: Introduce addfd ioctl to seccomp user notifier
Date: Sat, 30 May 2020 09:14:50 -0700	[thread overview]
Message-ID: <202005300911.AAE71F1955@keescook> (raw)
In-Reply-To: <20200530141329.tjrtrdy66jhqzojy@wittgenstein>

On Sat, May 30, 2020 at 04:13:29PM +0200, Christian Brauner wrote:
> On Fri, May 29, 2020 at 10:47:12PM -0700, Kees Cook wrote:
> > Oh hey! Look at scm_detach_fds_compat(). It needs this too. (And it's
> > missing the cgroup tracking.) That would fix:
> > 
> > 48a87cc26c13 ("net: netprio: fd passed in SCM_RIGHTS datagram not set correctly")
> > d84295067fc7 ("net: net_cls: fd passed in SCM_RIGHTS datagram not set correctly")
> > 
> > So, yes, let's get this fixed up. I'd say first fix the missing sock
> > update in the compat path (so it can be CCed stable). Then fix the missing
> 
> send this patch to net.
> 
> > sock update in pidfd_getfd() (so it can be CCed stable), then write the
> 
> send this patch to me.
> 
> > helper with a refactoring of scm_detach_fds(), scm_detach_fds_compat(),
> 
> this would be net-next most likely.
> 
> > and pidfd_getfd(). And then add the addfd seccomp user_notif ioctl cmd.
> 
> If you do this first, I'd suggest you resend the series here after all
> this has been merged. We're not in a rush since this won't make it for
> the 5.8 merge window anyway. By the time the changes land Kees might've
> applied my changes to his tree so you can rebase yours on top of it
> relieving Kees from fixing up merge conflicts.
> 
> About your potential net and net-next changes. Just in case you don't
> know - otherwise ignore this - please read and treat
> https://www.kernel.org/doc/Documentation/networking/netdev-FAQ.txt
> as the gospel. Also note, that after this Sunday - assuming Linus
> releases - net-next will be closed until the merge window is closed,
> i.e. for _at least_ 2 weeks. After the merge window closes you can check
> http://vger.kernel.org/~davem/net-next.html
> which either has a picture saying "Come In We're Open" or a sign saying
> "Sorry, We're Closed". Only send when the first sign is up or the wrath
> of Dave might hit you. :)

Yeah, timing is awkward here. I was originally thinking it could all
just land via seccomp (with appropriate Acks). Hmmm.

-- 
Kees Cook