From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>, Tejun Heo <tj@kernel.org>,
Andrew Vagin <avagin@openvz.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Serge Hallyn <serge.hallyn@canonical.com>,
Pavel Emelyanov <xemul@parallels.com>,
Vasiliy Kulikov <segoon@openwall.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Michael Kerrisk <mtk.manpages@gmail.com>
Subject: Re: [RFC 2/2] prctl: PR_SET_MM -- Introduce PR_SET_MM_MAP operation
Date: Wed, 9 Jul 2014 19:06:04 +0400 [thread overview]
Message-ID: <20140709150604.GN17860@moon.sw.swsoft.com> (raw)
In-Reply-To: <CAGXu5jKmTSb0YmNFDtr-jymrhy_s_PXUuvj3WKYffSU98gwyqg@mail.gmail.com>
On Wed, Jul 09, 2014 at 07:53:10AM -0700, Kees Cook wrote:
...
> > +
> > + /*
> > + * Make sure the pairs are ordered.
> > + */
> > +#define __prctl_check_order(__map, __m1, __m2) \
> > + (unsigned long)__map->__m2 <= (unsigned long)__map->__m1
> > + if (__prctl_check_order(prctl_map, start_code, end_code) ||
> > + __prctl_check_order(prctl_map, start_data, end_data) ||
> > + __prctl_check_order(prctl_map, arg_start, arg_end) ||
> > + __prctl_check_order(prctl_map, env_start, env_end))
> > + goto out;
> > +#undef __prctl_check_order
>
> This approach seems like a good solution given the security concerns
> with the earlier approach. I'm still pondering the implications, but
> as a minor style note, these macros are locally defined, but also all
> take at least a single identical argument in every usage. I would
> think it might be easier to read if they just used what they needed to
> directly.
>
> #define __prctl_check_addr_space(__member) \
> ((unsigned long)prctl_map->__member < mmap_max_addr && \
> (unsigned long)prctl_map->__member >= mmap_min_addr) ? 0 : -EINVAL
>
> #define __prctl_check_vma(__member) \
> find_vma(mm, (unsigned long)prctl_map->__member) ? 0 : -EINVAL
>
> Also, why change the symantics of the final macro? Seems like that one
> can use the same "error |=" style:
>
> #define __prctl_check_order(__m1, __m2) \
> prctl_map->__m1 < prctl_map->__m2 ? 0 : -EINVAL
Thanks a lot for comments, Kees! I tend to agre, leaving off the @prctl_map
variable out of macros should make code also shorter, I'll update that's
not the problem. Could you please re-check if I'm not missing something
in security aspects when time permits.
next prev parent reply other threads:[~2014-07-09 15:06 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-03 14:33 [RFC 0/2] prctl: set-mm -- Rework interface Cyrill Gorcunov
2014-07-03 14:33 ` [RFC 1/2] prctl: PR_SET_MM -- Factor out mmap_sem when update mm::exe_file Cyrill Gorcunov
2014-07-03 14:33 ` [RFC 2/2] prctl: PR_SET_MM -- Introduce PR_SET_MM_MAP operation Cyrill Gorcunov
2014-07-03 20:34 ` Cyrill Gorcunov
2014-07-04 7:52 ` Andrew Vagin
2014-07-04 8:11 ` Cyrill Gorcunov
2014-07-08 19:08 ` Cyrill Gorcunov
2014-07-08 21:38 ` Andrew Morton
2014-07-08 22:13 ` Cyrill Gorcunov
2014-07-09 14:13 ` Cyrill Gorcunov
2014-07-09 14:53 ` Kees Cook
2014-07-09 15:06 ` Cyrill Gorcunov [this message]
2014-07-11 17:36 ` Cyrill Gorcunov
2014-07-22 20:07 ` Kees Cook
2014-07-22 20:36 ` Cyrill Gorcunov
2014-07-24 13:48 ` Andrew Vagin
2014-07-24 16:42 ` Cyrill Gorcunov
2014-07-24 18:44 ` Kees Cook
2014-07-24 18:50 ` Cyrill Gorcunov
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