From: Jann Horn <jannh@google.com>
To: Tycho Andersen <tycho@tycho.pizza>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>,
Sargun Dhillon <sargun@sargun.me>,
Kees Cook <keescook@chromium.org>,
Christian Brauner <christian@brauner.io>,
linux-man <linux-man@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Aleksa Sarai <cyphar@cyphar.com>,
Alexei Starovoitov <ast@kernel.org>,
Will Drewry <wad@chromium.org>, bpf <bpf@vger.kernel.org>,
Song Liu <songliubraving@fb.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Andy Lutomirski <luto@amacapital.net>,
Linux Containers <containers@lists.linux-foundation.org>,
Giuseppe Scrivano <gscrivan@redhat.com>,
Robert Sesek <rsesek@google.com>
Subject: Re: For review: seccomp_user_notif(2) manual page
Date: Thu, 1 Oct 2020 01:11:33 +0200 [thread overview]
Message-ID: <CAG48ez1VOUEHVQyo-2+uO7J+-jN5rh7=KmrMJiPaFjwCbKR1Sg@mail.gmail.com> (raw)
In-Reply-To: <20200930230327.GA1260245@cisco>
On Thu, Oct 1, 2020 at 1:03 AM Tycho Andersen <tycho@tycho.pizza> wrote:
> On Wed, Sep 30, 2020 at 10:34:51PM +0200, Michael Kerrisk (man-pages) wrote:
> > On 9/30/20 5:03 PM, Tycho Andersen wrote:
> > > On Wed, Sep 30, 2020 at 01:07:38PM +0200, Michael Kerrisk (man-pages) wrote:
> > >> ┌─────────────────────────────────────────────────────┐
> > >> │FIXME │
> > >> ├─────────────────────────────────────────────────────┤
> > >> │From my experiments, it appears that if a SEC‐ │
> > >> │COMP_IOCTL_NOTIF_RECV is done after the target │
> > >> │process terminates, then the ioctl() simply blocks │
> > >> │(rather than returning an error to indicate that the │
> > >> │target process no longer exists). │
> > >
> > > Yeah, I think Christian wanted to fix this at some point,
> >
> > Do you have a pointer that discussion? I could not find it with a
> > quick search.
> >
> > > but it's a
> > > bit sticky to do.
> >
> > Can you say a few words about the nature of the problem?
>
> I remembered wrong, it's actually in the tree: 99cdb8b9a573 ("seccomp:
> notify about unused filter"). So maybe there's a bug here?
That thing only notifies on ->poll, it doesn't unblock ioctls; and
Michael's sample code uses SECCOMP_IOCTL_NOTIF_RECV to wait. So that
commit doesn't have any effect on this kind of usage.
next prev parent reply other threads:[~2020-09-30 23:19 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 11:07 For review: seccomp_user_notif(2) manual page Michael Kerrisk (man-pages)
2020-09-30 15:03 ` Tycho Andersen
2020-09-30 15:11 ` Tycho Andersen
2020-09-30 20:34 ` Michael Kerrisk (man-pages)
2020-09-30 23:03 ` Tycho Andersen
2020-09-30 23:11 ` Jann Horn [this message]
2020-09-30 23:24 ` Tycho Andersen
2020-10-01 1:52 ` Jann Horn
2020-10-01 2:14 ` Jann Horn
2020-10-25 16:31 ` Michael Kerrisk (man-pages)
2020-10-26 15:54 ` Jann Horn
2020-10-27 6:14 ` Michael Kerrisk (man-pages)
2020-10-27 10:28 ` Jann Horn
2020-10-28 6:31 ` Sargun Dhillon
2020-10-28 9:43 ` Jann Horn
2020-10-28 17:43 ` Sargun Dhillon
2020-10-28 18:20 ` Jann Horn
2020-10-01 7:49 ` Michael Kerrisk (man-pages)
2020-10-26 0:32 ` Kees Cook
2020-10-26 9:51 ` Jann Horn
2020-10-26 10:31 ` Jann Horn
2020-10-28 22:56 ` Kees Cook
2020-10-29 1:11 ` Jann Horn
[not found] ` <20201029021348.GB25673@cisco>
2020-10-29 4:26 ` Jann Horn
2020-10-28 22:53 ` Kees Cook
2020-10-29 1:25 ` Jann Horn
2020-10-01 7:45 ` Michael Kerrisk (man-pages)
2020-10-14 4:40 ` Michael Kerrisk (man-pages)
2020-09-30 15:53 ` Jann Horn
2020-10-01 12:54 ` Christian Brauner
2020-10-01 15:47 ` Jann Horn
2020-10-01 16:58 ` Tycho Andersen
2020-10-01 17:12 ` Christian Brauner
2020-10-14 5:41 ` Michael Kerrisk (man-pages)
2020-10-01 18:18 ` Jann Horn
2020-10-01 18:56 ` Tycho Andersen
2020-10-01 17:05 ` Christian Brauner
2020-10-15 11:24 ` Michael Kerrisk (man-pages)
2020-10-15 20:32 ` Jann Horn
2020-10-16 18:29 ` Michael Kerrisk (man-pages)
2020-10-17 0:25 ` Jann Horn
2020-10-24 12:52 ` Michael Kerrisk (man-pages)
2020-10-26 9:32 ` Jann Horn
2020-10-26 9:47 ` Michael Kerrisk (man-pages)
2020-09-30 23:39 ` Kees Cook
2020-10-15 11:24 ` Michael Kerrisk (man-pages)
2020-10-26 0:19 ` Kees Cook
2020-10-26 9:39 ` Michael Kerrisk (man-pages)
2020-10-01 12:36 ` Christian Brauner
2020-10-15 11:23 ` Michael Kerrisk (man-pages)
2020-10-01 21:06 ` Sargun Dhillon
2020-10-01 23:19 ` Tycho Andersen
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