From: Jamie Lokier <jamie@shareable.org>
To: Will Drewry <wad@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org, keescook@chromium.org,
john.johansen@canonical.com, serge.hallyn@canonical.com,
coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com,
djm@mindrot.org, torvalds@linux-foundation.org,
segoon@openwall.com, jmorris@namei.org, scarybeasts@gmail.com,
avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk,
luto@mit.edu, mingo@elte.hu, akpm@linux-foundation.org,
khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com,
oleg@redhat.com, ak@linux.intel.com, eric.dumazet@gmail.com,
gregkh@suse.de, dhowells@redhat.com, daniel.lezcano@free.fr,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org, olofj@chromium.org,
mhalcrow@google.com, dlaor@redhat.com
Subject: Re: [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF
Date: Fri, 13 Jan 2012 01:34:46 +0000 [thread overview]
Message-ID: <20120113013446.GU7180@jl-vm1.vm.bytemark.co.uk> (raw)
In-Reply-To: <CABqD9hZUMpmS9yeJYfBZD8eTvS6MC6g8Cw+88SxDP520Jd0DNw@mail.gmail.com>
Will Drewry wrote:
> >> > There's already a security model around who can use ptrace(); speeding
> >> > it up needn't break that.
> >> >
> >> > If we'd had BPF ptrace in the first place, SECCOMP wouldn't have been
> >> > needed as userspace could have done it, with exactly the restrictions
> >> > it wants. Google's NaCl comes to mind as a potential user.
> >>
> >> That's not entirely true. ptrace supervisors are subject to races and
> >> always fail open. This makes them effective but not as robust as a
> >> seccomp solution can provide.
> >
> > What races do you know about?
>
> I'm pretty sure that if you have two "isolated" processes, they could
> cause irregular behavior using signals.
Do you have an example? I'm not aware of one and I've been studying
ptrace quite a bit lately. If there's a race (other than temporary
kernel bugs with all the ptrace patching lately ;-), I would like to
know and maybe patch it.
The only signal confusion when ptracing syscalls I'm aware of is with
SIGTRAP, and that was fixed in 2.5.46, long, long ago (PTRACE_SETOPTIONS).
> > I'm not aware of any ptrace races if it's used properly. I'm also not
> > sure what you mean by fail open/close here, unless you mean the target
> > process gets to carry on if the tracing process dies.
>
> Exactly. Security systems that, on failure, allow the action to
> proceed can't be relied on.
That's fair enough. There are numerous occasions when ptracer death
should kill the tracee anyway regardless of security. E.g. "strace
command..." and strace dies, you'd normally want the command to
be killed as well. So that could be worth a ptrace option anyway.
Thanks,
-- Jamie
next prev parent reply other threads:[~2012-01-13 1:34 UTC|newest]
Thread overview: 222+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 17:25 [RFC,PATCH 0/2] dynamic seccomp policies (using BPF filters) Will Drewry
2012-01-11 17:25 ` [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF Will Drewry
2012-01-12 8:53 ` Serge Hallyn
2012-01-12 16:54 ` Will Drewry
2012-01-12 14:50 ` Oleg Nesterov
2012-01-12 16:55 ` Will Drewry
2012-01-12 15:43 ` Steven Rostedt
2012-01-12 16:14 ` Oleg Nesterov
2012-01-12 16:38 ` Steven Rostedt
2012-01-12 16:47 ` Oleg Nesterov
2012-01-12 17:08 ` Will Drewry
2012-01-12 17:30 ` Jamie Lokier
2012-01-12 17:40 ` Steven Rostedt
2012-01-12 17:44 ` Jamie Lokier
2012-01-12 17:56 ` Steven Rostedt
2012-01-12 23:27 ` Alan Cox
2012-01-12 23:38 ` Linus Torvalds
2012-01-12 22:18 ` Will Drewry
2012-01-12 23:00 ` Andrew Lutomirski
2012-01-12 16:14 ` Andrew Lutomirski
2012-01-12 16:27 ` Steven Rostedt
2012-01-12 16:51 ` Andrew Lutomirski
2012-01-12 17:09 ` Linus Torvalds
2012-01-12 17:17 ` Steven Rostedt
2012-01-12 18:18 ` Andrew Lutomirski
2012-01-12 18:32 ` Linus Torvalds
2012-01-12 18:44 ` Andrew Lutomirski
2012-01-12 19:08 ` Kyle Moffett
2012-01-12 23:05 ` Eric Paris
2012-01-12 23:33 ` Andrew Lutomirski
2012-01-12 19:40 ` Will Drewry
2012-01-12 19:42 ` Will Drewry
2012-01-12 19:46 ` Andrew Lutomirski
2012-01-12 20:00 ` Linus Torvalds
2012-01-12 16:59 ` Will Drewry
2012-01-12 17:22 ` Jamie Lokier
2012-01-12 17:35 ` Will Drewry
2012-01-12 17:57 ` Jamie Lokier
2012-01-12 18:03 ` Will Drewry
2012-01-13 1:34 ` Jamie Lokier [this message]
2012-01-13 6:33 ` Chris Evans
2012-01-12 17:36 ` Jamie Lokier
2012-01-12 16:18 ` Alan Cox
2012-01-12 17:03 ` Will Drewry
2012-01-12 17:11 ` Alan Cox
2012-01-12 17:52 ` Will Drewry
2012-01-13 1:31 ` James Morris
2012-01-12 16:22 ` Oleg Nesterov
2012-01-12 17:10 ` Will Drewry
2012-01-12 17:23 ` Oleg Nesterov
2012-01-12 17:51 ` Will Drewry
2012-01-13 17:31 ` Oleg Nesterov
2012-01-13 19:01 ` Will Drewry
2012-01-13 23:10 ` Will Drewry
2012-01-13 23:12 ` Will Drewry
2012-01-13 23:30 ` Eric Paris
2012-01-16 18:37 ` Oleg Nesterov
2012-01-16 20:15 ` Will Drewry
2012-01-17 16:45 ` Oleg Nesterov
2012-01-17 16:56 ` Will Drewry
2012-01-17 17:01 ` Andrew Lutomirski
2012-01-17 17:05 ` Oleg Nesterov
2012-01-17 17:45 ` Andrew Lutomirski
2012-01-18 0:56 ` Compat 32-bit syscall entry from 64-bit task!? [was: Re: [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF] Indan Zupancic
2012-01-18 1:01 ` Andrew Lutomirski
2012-01-19 1:06 ` Indan Zupancic
2012-01-19 1:19 ` Andrew Lutomirski
2012-01-19 1:47 ` Indan Zupancic
2012-01-18 1:07 ` Roland McGrath
2012-01-18 1:47 ` Indan Zupancic
2012-01-18 1:48 ` Jamie Lokier
2012-01-18 1:50 ` Andi Kleen
2012-01-18 2:00 ` Steven Rostedt
2012-01-18 2:04 ` Jamie Lokier
2012-01-18 2:22 ` Andi Kleen
2012-01-18 2:25 ` Andrew Lutomirski
2012-01-18 4:22 ` Indan Zupancic
2012-01-18 5:23 ` Linus Torvalds
2012-01-18 6:25 ` Linus Torvalds
2012-01-18 13:12 ` Compat 32-bit syscall entry from 64-bit task!? Indan Zupancic
2012-01-18 19:31 ` Linus Torvalds
2012-01-18 19:36 ` Andi Kleen
2012-01-18 19:39 ` Linus Torvalds
2012-01-18 19:44 ` Andi Kleen
2012-01-18 19:47 ` Linus Torvalds
2012-01-18 19:52 ` Will Drewry
2012-01-18 19:58 ` Will Drewry
2012-01-18 19:41 ` Martin Mares
2012-01-18 19:38 ` Andrew Lutomirski
2012-01-19 16:01 ` Jamie Lokier
2012-01-19 16:13 ` Andrew Lutomirski
2012-01-19 19:21 ` Linus Torvalds
2012-01-19 19:30 ` Andrew Lutomirski
2012-01-19 19:37 ` Linus Torvalds
2012-01-19 19:41 ` Linus Torvalds
2012-01-19 23:54 ` Jamie Lokier
2012-01-20 0:05 ` Linus Torvalds
2012-01-20 15:35 ` Will Drewry
2012-01-20 17:56 ` Roland McGrath
2012-01-20 19:45 ` Will Drewry
2012-01-18 20:26 ` Linus Torvalds
2012-01-18 20:55 ` H. Peter Anvin
2012-01-18 21:01 ` Linus Torvalds
2012-01-18 21:04 ` H. Peter Anvin
2012-01-18 21:21 ` H. Peter Anvin
2012-01-18 21:51 ` Roland McGrath
2012-01-18 21:53 ` H. Peter Anvin
2012-01-18 23:28 ` Linus Torvalds
2012-01-19 0:38 ` H. Peter Anvin
2012-01-20 21:51 ` Denys Vlasenko
2012-01-20 22:40 ` Roland McGrath
2012-01-20 22:41 ` H. Peter Anvin
2012-01-20 23:49 ` Indan Zupancic
2012-01-20 23:55 ` Roland McGrath
2012-01-20 23:58 ` hpanvin@gmail.com
2012-01-23 2:14 ` Indan Zupancic
2012-01-21 0:07 ` Denys Vlasenko
2012-01-21 0:10 ` Roland McGrath
2012-01-21 1:23 ` Jamie Lokier
2012-01-23 2:37 ` Indan Zupancic
2012-01-23 16:48 ` Oleg Nesterov
2012-01-24 8:19 ` Indan Zupancic
2012-02-06 20:30 ` H. Peter Anvin
2012-02-06 20:39 ` Roland McGrath
2012-02-06 20:42 ` H. Peter Anvin
2012-01-18 21:26 ` Linus Torvalds
2012-01-18 21:30 ` H. Peter Anvin
2012-01-18 21:42 ` Linus Torvalds
2012-01-18 21:47 ` H. Peter Anvin
2012-01-19 1:45 ` Indan Zupancic
2012-01-19 2:16 ` H. Peter Anvin
2012-02-06 8:32 ` Indan Zupancic
2012-02-06 17:02 ` H. Peter Anvin
2012-02-07 1:52 ` Indan Zupancic
2012-02-09 0:19 ` H. Peter Anvin
2012-02-09 4:20 ` Indan Zupancic
2012-02-09 4:29 ` H. Peter Anvin
2012-02-09 6:03 ` Indan Zupancic
2012-02-09 14:47 ` H. Peter Anvin
2012-02-09 16:00 ` H.J. Lu
2012-02-10 1:09 ` Indan Zupancic
2012-02-10 1:15 ` H. Peter Anvin
2012-02-10 2:29 ` Indan Zupancic
2012-02-10 2:47 ` H. Peter Anvin
[not found] ` <cc95fcf4b1c28ee6f73e373d04593634.squirrel@webmail.greenhost.nl>
2012-02-10 15:53 ` H. Peter Anvin
2012-02-10 22:42 ` Indan Zupancic
2012-02-10 22:56 ` H. Peter Anvin
2012-02-12 12:07 ` Indan Zupancic
2012-01-25 19:36 ` Oleg Nesterov
2012-01-25 20:20 ` Pedro Alves
2012-01-25 23:36 ` Denys Vlasenko
2012-01-25 23:32 ` Denys Vlasenko
2012-01-26 0:40 ` Indan Zupancic
2012-01-26 1:08 ` Jamie Lokier
2012-01-26 1:22 ` Denys Vlasenko
2012-01-26 6:34 ` Indan Zupancic
2012-01-26 10:31 ` Jamie Lokier
2012-01-26 10:40 ` Denys Vlasenko
2012-01-26 11:01 ` Jamie Lokier
2012-01-26 14:02 ` Denys Vlasenko
2012-01-26 11:19 ` Indan Zupancic
2012-01-26 11:20 ` Indan Zupancic
2012-01-26 11:47 ` Jamie Lokier
2012-01-26 14:05 ` Denys Vlasenko
2012-01-27 7:23 ` Indan Zupancic
2012-02-10 2:02 ` Jamie Lokier
2012-02-10 3:37 ` Indan Zupancic
2012-02-10 21:19 ` Denys Vlasenko
2012-01-26 1:09 ` Denys Vlasenko
2012-01-26 3:47 ` Linus Torvalds
2012-01-26 18:03 ` Denys Vlasenko
2017-03-08 23:41 ` Dmitry V. Levin
2017-03-09 4:39 ` Andrew Lutomirski
2017-03-14 2:57 ` Dmitry V. Levin
2012-01-26 5:57 ` Indan Zupancic
2012-01-26 0:59 ` Jamie Lokier
2012-01-26 1:21 ` Denys Vlasenko
2012-01-26 8:23 ` Pedro Alves
2012-01-26 8:53 ` Denys Vlasenko
2012-01-26 9:51 ` Pedro Alves
2012-01-26 18:44 ` Oleg Nesterov
2012-02-10 2:51 ` Jamie Lokier
2012-01-18 15:04 ` Compat 32-bit syscall entry from 64-bit task!? [was: Re: [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF] Eric Paris
2012-01-18 17:51 ` Linus Torvalds
2012-01-18 5:43 ` Chris Evans
2012-01-18 12:12 ` Indan Zupancic
2012-01-18 21:13 ` Chris Evans
2012-01-19 0:14 ` Indan Zupancic
2012-01-19 8:16 ` Chris Evans
2012-01-19 11:34 ` Indan Zupancic
2012-01-19 16:11 ` Jamie Lokier
2012-01-19 15:40 ` Jamie Lokier
2012-01-18 17:00 ` Oleg Nesterov
2012-01-18 17:12 ` Oleg Nesterov
2012-01-18 21:09 ` Chris Evans
2012-01-23 16:56 ` Oleg Nesterov
2012-01-23 22:23 ` Chris Evans
2012-02-07 11:45 ` Indan Zupancic
2012-01-19 0:29 ` Indan Zupancic
2012-01-18 2:27 ` Linus Torvalds
2012-01-18 2:31 ` Andi Kleen
2012-01-18 2:46 ` Linus Torvalds
2012-01-18 14:06 ` Martin Mares
2012-01-18 18:24 ` Andi Kleen
2012-01-19 16:04 ` Jamie Lokier
2012-01-20 0:21 ` Indan Zupancic
2012-01-20 0:53 ` Linus Torvalds
2012-01-20 2:02 ` Indan Zupancic
2012-01-17 17:06 ` [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF Will Drewry
2012-01-17 19:35 ` Will Drewry
2012-01-12 17:02 ` Andrew Lutomirski
2012-01-16 20:28 ` Will Drewry
2012-01-11 17:25 ` [RFC,PATCH 2/2] Documentation: prctl/seccomp_filter Will Drewry
2012-01-11 20:03 ` Jonathan Corbet
2012-01-11 20:10 ` Will Drewry
2012-01-11 23:19 ` [PATCH v2 " Will Drewry
2012-01-12 0:29 ` Will Drewry
2012-01-12 18:16 ` Randy Dunlap
2012-01-12 17:23 ` Will Drewry
2012-01-12 17:34 ` Steven Rostedt
2012-01-12 13:13 ` [RFC,PATCH " Łukasz Sowa
2012-01-12 17:25 ` Will Drewry
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