Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters

From	Kees Cook <keescook@chromium.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters
Date	2015-10-26 07:50 +0100
Message-ID	<qnJLs-4TL-13@gated-at.bofh.it> (permalink)
References	(4 earlier) <qm6Ma-3fF-13@gated-at.bofh.it> <qm75w-3ST-21@gated-at.bofh.it> <qm8XF-6Ci-27@gated-at.bofh.it> <qm9h0-6Z6-17@gated-at.bofh.it> <qnuMq-4bC-17@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Mon, Oct 26, 2015 at 12:39 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> On 10/21, Tycho Andersen wrote:
>>
>> > And this leads to another question... If we expect that this interface
>> > can change later, then perhaps PTRACE_SECCOMP_GET_FILTER should also
>> > dump some header before copy_to_user(fprog->filter) ? Say, just
>> > "unsigned long version" == 0 for now. So that we can avoid
>> > PTRACE_SECCOMP_GET_FILTER_V2 in future.
>>
>> So this is interesting. Like Kees mentioned, the bulk of the work
>> would be done by the bpf syscall. We'd still need some way to get
>> access to the fd itself, which we could (ab)use
>> PTRACE_SECCOMP_GET_FILTER for, by returning the fd + BPF_MAXINSNS (so
>> that it doesn't conflict with length) or something like that. Or add a
>> _V2 as you say. If there is some change we can make to have a nicer
>> interface than fd + BPF_MAXINSNS to future proof, I'm fine with making
>> it.
>
> Can't comment, this is up to you/Kees ;)
>
> So, just in case, let me repeat I am fine with this patch.

Cool, thanks. I'll get this into my tree after kernel summit. Thanks
for suffering through all this Tycho!

-Kees

-- 
Kees Cook
Chrome OS Security
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

v8 of seccomp filter c/r Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-20 22:00 +0200
  [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-20 22:00 +0200
    Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Kees Cook <keescook@chromium.org> - 2015-10-20 22:30 +0200
      Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-20 22:40 +0200
    Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Oleg Nesterov <oleg@redhat.com> - 2015-10-20 22:30 +0200
      Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-21 00:10 +0200
        Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Oleg Nesterov <oleg@redhat.com> - 2015-10-21 21:00 +0200
          Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-21 21:20 +0200
            Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Kees Cook <keescook@chromium.org> - 2015-10-21 22:20 +0200
              Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Daniel Borkmann <daniel@iogearbox.net> - 2015-10-21 22:20 +0200
                Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-21 22:40 +0200
            Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Oleg Nesterov <oleg@redhat.com> - 2015-10-21 23:20 +0200
              Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Kees Cook <keescook@chromium.org> - 2015-10-21 23:30 +0200
              Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-21 23:40 +0200
                Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Oleg Nesterov <oleg@redhat.com> - 2015-10-25 15:50 +0100
                Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Kees Cook <keescook@chromium.org> - 2015-10-26 07:50 +0100
                Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Kees Cook <keescook@chromium.org> - 2015-10-26 08:10 +0100
                Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp  filters Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-27 01:10 +0100
                Re: [PATCH v8] seccomp, ptrace: add support for dumping seccomp filters Daniel Borkmann <daniel@iogearbox.net> - 2015-10-27 01:20 +0100

csiph-web