From: Jann Horn <jannh@google.com>
To: Tycho Andersen <tycho@tycho.ws>
Cc: Kees Cook <keescook@chromium.org>,
kernel list <linux-kernel@vger.kernel.org>,
containers@lists.linux-foundation.org,
Linux API <linux-api@vger.kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Oleg Nesterov <oleg@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Serge E. Hallyn" <serge@hallyn.com>,
Christian Brauner <christian.brauner@ubuntu.com>,
Tyler Hicks <tyhicks@canonical.com>,
suda.akihiro@lab.ntt.co.jp, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v7 5/6] seccomp: add a way to pass FDs via a notification fd
Date: Fri, 28 Sep 2018 00:17:07 +0200 [thread overview]
Message-ID: <CAG48ez3LYZiEQJKf+6UxjeM0L7FXEq_qxZVb=O=sJeQ2DadbNg@mail.gmail.com> (raw)
In-Reply-To: <20180927221408.GD15491@cisco.cisco.com>
On Fri, Sep 28, 2018 at 12:14 AM Tycho Andersen <tycho@tycho.ws> wrote:
> On Thu, Sep 27, 2018 at 09:28:07PM +0200, Jann Horn wrote:
> > On Thu, Sep 27, 2018 at 5:11 PM Tycho Andersen <tycho@tycho.ws> wrote:
> > > This patch adds a way to insert FDs into the tracee's process (also
> > > close/overwrite fds for the tracee). This functionality is necessary to
> > > mock things like socketpair() or dup2() or similar, but since it depends on
> > > external (vfs) patches, I've left it as a separate patch as before so the
> > > core functionality can still be merged while we argue about this. Except
> > > this time it doesn't add any ugliness to the API :)
> > [...]
> > > +static long seccomp_notify_put_fd(struct seccomp_filter *filter,
> > > + unsigned long arg)
> > > +{
> > > + struct seccomp_notif_put_fd req;
> > > + void __user *buf = (void __user *)arg;
> > > + struct seccomp_knotif *knotif = NULL;
> > > + long ret;
> > > +
> > > + if (copy_from_user(&req, buf, sizeof(req)))
> > > + return -EFAULT;
> > > +
> > > + if (req.fd < 0 && req.to_replace < 0)
> > > + return -EINVAL;
> > > +
> > > + ret = mutex_lock_interruptible(&filter->notify_lock);
> > > + if (ret < 0)
> > > + return ret;
> > > +
> > > + ret = -ENOENT;
> > > + list_for_each_entry(knotif, &filter->notif->notifications, list) {
> > > + struct file *file = NULL;
> > > +
> > > + if (knotif->id != req.id)
> > > + continue;
> >
> > Are you intentionally permitting non-SENT states here? It shouldn't
> > make a big difference, but I think it'd be nice to at least block the
> > use of notifications in SECCOMP_NOTIFY_REPLIED state.
>
> Agreed, I'll block everything besides REPLIED.
Do you mean SENT? In REPLIED state, seccomp_notify_put_fd()
is racy because the target task is in the process of waking up, right?
next prev parent reply other threads:[~2018-09-28 4:38 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-27 15:11 [PATCH v7 0/6] seccomp trap to userspace Tycho Andersen
2018-09-27 15:11 ` [PATCH v7 1/6] seccomp: add a return code to " Tycho Andersen
2018-09-27 21:31 ` Kees Cook
2018-09-27 22:48 ` Tycho Andersen
2018-09-27 23:10 ` Kees Cook
2018-09-28 14:39 ` Tycho Andersen
2018-10-08 14:58 ` Christian Brauner
2018-10-09 14:28 ` Tycho Andersen
2018-10-09 16:24 ` Christian Brauner
2018-10-09 16:29 ` Tycho Andersen
2018-10-17 20:29 ` Tycho Andersen
2018-10-17 22:21 ` Kees Cook
2018-10-17 22:33 ` Tycho Andersen
2018-10-21 16:04 ` Tycho Andersen
2018-10-22 9:42 ` Christian Brauner
2018-09-27 21:51 ` Jann Horn
2018-09-27 22:45 ` Kees Cook
2018-09-27 23:08 ` Tycho Andersen
2018-09-27 23:04 ` Tycho Andersen
2018-09-27 23:37 ` Jann Horn
2018-09-29 0:28 ` Aleksa Sarai
2018-09-27 15:11 ` [PATCH v7 2/6] seccomp: make get_nth_filter available outside of CHECKPOINT_RESTORE Tycho Andersen
2018-09-27 16:51 ` Jann Horn
2018-09-27 21:42 ` Kees Cook
2018-10-08 13:55 ` Christian Brauner
2018-09-27 15:11 ` [PATCH v7 3/6] seccomp: add a way to get a listener fd from ptrace Tycho Andersen
2018-09-27 16:20 ` Jann Horn
2018-09-27 16:34 ` Tycho Andersen
2018-09-27 17:35 ` Jann Horn
2018-09-27 18:09 ` Tycho Andersen
2018-09-27 21:53 ` Kees Cook
2018-10-08 15:16 ` Christian Brauner
2018-10-08 15:33 ` Jann Horn
2018-10-08 16:21 ` Christian Brauner
2018-10-08 16:42 ` Jann Horn
2018-10-08 18:18 ` Christian Brauner
2018-10-09 12:39 ` Jann Horn
2018-10-09 13:28 ` Christian Brauner
2018-10-09 13:36 ` Jann Horn
2018-10-09 13:49 ` Christian Brauner
2018-10-09 13:50 ` Jann Horn
2018-10-09 14:09 ` Christian Brauner
2018-10-09 15:26 ` Jann Horn
2018-10-09 16:20 ` Christian Brauner
2018-10-09 16:26 ` Jann Horn
2018-10-10 12:54 ` Christian Brauner
2018-10-10 13:09 ` Christian Brauner
2018-10-10 13:10 ` Jann Horn
2018-10-10 13:18 ` Christian Brauner
2018-10-10 15:31 ` Paul Moore
2018-10-10 15:33 ` Jann Horn
2018-10-10 15:39 ` Christian Brauner
2018-10-10 16:54 ` Tycho Andersen
2018-10-10 17:15 ` Christian Brauner
2018-10-10 17:26 ` Tycho Andersen
2018-10-10 18:28 ` Christian Brauner
2018-10-11 7:24 ` Paul Moore
2018-10-11 13:39 ` Jann Horn
2018-10-11 23:10 ` Paul Moore
2018-10-12 1:02 ` Andy Lutomirski
2018-10-12 20:02 ` Tycho Andersen
2018-10-12 20:06 ` Jann Horn
2018-10-12 20:11 ` Christian Brauner
2018-10-08 18:00 ` Tycho Andersen
2018-10-08 18:41 ` Christian Brauner
2018-10-10 17:45 ` Andy Lutomirski
2018-10-10 18:26 ` Christian Brauner
2018-09-27 15:11 ` [PATCH v7 4/6] files: add a replace_fd_files() function Tycho Andersen
2018-09-27 16:49 ` Jann Horn
2018-09-27 18:04 ` Tycho Andersen
2018-09-27 21:59 ` Kees Cook
2018-09-28 2:20 ` Kees Cook
2018-09-28 2:46 ` Jann Horn
2018-09-28 5:23 ` Tycho Andersen
2018-09-27 15:11 ` [PATCH v7 5/6] seccomp: add a way to pass FDs via a notification fd Tycho Andersen
2018-09-27 16:39 ` Jann Horn
2018-09-27 22:13 ` Tycho Andersen
2018-09-27 19:28 ` Jann Horn
2018-09-27 22:14 ` Tycho Andersen
2018-09-27 22:17 ` Jann Horn [this message]
2018-09-27 22:49 ` Tycho Andersen
2018-09-27 22:09 ` Kees Cook
2018-09-27 22:15 ` Tycho Andersen
2018-09-27 15:11 ` [PATCH v7 6/6] samples: add an example of seccomp user trap Tycho Andersen
2018-09-27 22:11 ` Kees Cook
2018-09-28 21:57 ` [PATCH v7 0/6] seccomp trap to userspace Michael Kerrisk (man-opages)
2018-09-28 22:03 ` Tycho Andersen
2018-09-28 22:16 ` Michael Kerrisk (man-pages)
2018-09-28 22:34 ` Kees Cook
2018-09-28 22:46 ` Michael Kerrisk (man-pages)
2018-09-28 22:48 ` Jann Horn
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