From: Will Drewry <wad@chromium.org>
To: Andrew Lutomirski <luto@mit.edu>
Cc: 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, rostedt@goodmis.org, jmorris@namei.org,
scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi,
viro@zeniv.linux.org.uk, 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: Mon, 16 Jan 2012 14:28:25 -0600 [thread overview]
Message-ID: <CABqD9hZ5vZwDNcD37pGRcU+=qvffzJshqSU2pYPF+weMkhY8vg@mail.gmail.com> (raw)
In-Reply-To: <CAObL_7FMuomx-fAKUHA2mHAQrLSOOKF0=4ugkvk2b8rfFXk3EQ@mail.gmail.com>
On Thu, Jan 12, 2012 at 11:02 AM, Andrew Lutomirski <luto@mit.edu> wrote:
> On Wed, Jan 11, 2012 at 9:25 AM, Will Drewry <wad@chromium.org> wrote:
>> This patch adds support for seccomp mode 2. This mode enables dynamic
>> enforcement of system call filtering policy in the kernel as specified
>> by a userland task. The policy is expressed in terms of a BPF program,
>> as is used for userland-exposed socket filtering. Instead of network
>> data, the BPF program is evaluated over struct user_regs_struct at the
>> time of the system call (as retrieved using regviews).
>>
>https://www.google.com/calendar?tab=mc&authuser=1
> There's some seccomp-related code in the vsyscall emulation path in
> arch/x86/kernel/vsyscall_64.c. How should time(), getcpu(), and
> gettimeofday() be handled?
Nice catch:
lxr.linux.no/linux+v3.2.1/arch/x86/kernel/vsyscall_64.c#L180
I'd missed it.
> If you want filtering to work, there
> aren't any real syscall registers to inspect, but they could be
> synthesized.
Hrm, I wonder if making sure orig_eax is populated with the
vsyscall_nr would be enough. Unless I'm misreading, args 0 and 1 are
correct, so there may be other noise, but performing a call to
__secure_computing() (either in the case or with a pre-validate
syscall nr: 0-2) should send the do_exit. Does that sound reasonable?
I'll try to do the right thing in my next patch set.
> Preventing a malicious task from figuring out approximately what time
> it is is basically impossible because of the way that vvars work. I
> don't know how to change that efficiently.
There are other ways to guess the time too, so I don't think it's that
bad. For those that are really worried, they could disable or
otherwise attempt to limit vsyscall access from their sandbox.
thanks!
will
next prev parent reply other threads:[~2012-01-16 20:28 UTC|newest]
Thread overview: 235+ 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
2012-01-13 2:44 ` Indan Zupancic
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
2012-01-15 3:40 ` Indan Zupancic
2012-01-16 1:40 ` Will Drewry
2012-01-16 6:49 ` Indan Zupancic
2012-01-16 20:12 ` Will Drewry
2012-01-17 6:46 ` Indan Zupancic
2012-01-17 17:37 ` Will Drewry
2012-01-18 4:06 ` Indan Zupancic
2012-01-18 4:38 ` Will Drewry
2012-01-17 20:34 ` Kees Cook
2012-01-17 20:42 ` Will Drewry
2012-01-17 21:09 ` Will Drewry
2012-01-18 4:47 ` Indan Zupancic
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 [this message]
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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