From: Richard Weinberger <richard-/L3Ra7n9ekc@public.gmane.org>
To: "Eric W. Biederman"
<ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>,
Linux Containers
<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
Cc: Seth Forshee
<seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Al Viro <viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>,
Kenton Varda <kenton-AuYgBwuPrUQTaNkGU808tA@public.gmane.org>,
Michael Kerrisk-manpages
<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Greg Kroah-Hartman
<gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Ivan Delalande <colona-nzgTgzXrdUbQT0dZR+AlfA@public.gmane.org>,
Linus Torvalds
<torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Subject: Re: [REVIEW][PATCH 1/2] vfs: Commit to never having exectuables on proc and sysfs.
Date: Fri, 10 Jul 2015 20:24:41 +0200 [thread overview]
Message-ID: <55A00DE9.7060806@nod.at> (raw)
In-Reply-To: <87h9pcyokc.fsf_-_-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
Am 10.07.2015 um 18:17 schrieb Eric W. Biederman:
>
> Today proc and sysfs do not contain any executable files. Several
> applications today mount proc or sysfs without noexec and nosuid and
> then depend on there being no exectuables files on proc or sysfs.
> Having any executable files show on proc or sysfs would cause
> a user space visible regression, and most likely security problems.
>
> Therefore commit to never allowing executables on proc and sysfs by
> adding a new flag to mark them as filesystems without executables and
> enforce that flag.
>
> Test the flag where MNT_NOEXEC is tested today, so that the only user
> visible effect will be that exectuables will be treated as if the
> execute bit is cleared.
>
> The filesystems proc and sysfs do not currently incoporate any
> executable files so this does not result in any user visible effects.
>
> This makes it unnecessary to vet changes to proc and sysfs tightly for
> adding exectuable files or changes to chattr that would modify
> existing files, as no matter what the individual file say they will
> not be treated as exectuable files by the vfs.
>
> Not having to vet changes to closely is important as without this we
> are only one proc_create call (or another goof up in the
> implementation of notify_change) from having problematic executables
> on proc. Those mistakes are all too easy to make and would create
> a situation where there are security issues or the assumptions of
> some program having to be broken (and cause userspace regressions).
Would it make sense to add SB_I_NOEXEC to more pseudo filesystems?
Say pstore or devpts?
Thanks,
//richard
next prev parent reply other threads:[~2015-07-10 18:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-26 20:50 [GIT PULL] User namespace related fixes for v4.2 Eric W. Biederman
[not found] ` <CA+55aFysKDXr2HEwNzm3z9QOw=E4ZeWcvYQ-xLhy5_k+rGbeRg@mail.gmail.com>
[not found] ` <CA+55aFysKDXr2HEwNzm3z9QOw=E4ZeWcvYQ-xLhy5_k+rGbeRg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-06-29 21:13 ` Eric W. Biederman
[not found] ` <87pp4eqktr.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2015-07-03 22:10 ` Linus Torvalds
[not found] ` <CA+55aFw-DK-xDC-3HYa=BMX8WNyQgT9O01tihrAS9+-7PPj_jA@mail.gmail.com>
[not found] ` <CA+55aFw-DK-xDC-3HYa=BMX8WNyQgT9O01tihrAS9+-7PPj_jA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-07-04 23:11 ` Al Viro
[not found] ` <20150704231118.GT17109-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2015-07-10 16:16 ` [REVIEW][PATCH 0/2] noexec on proc and sysfs Eric W. Biederman
[not found] ` <87mvz4yomp.fsf_-_@x220.int.ebiederm.org>
[not found] ` <87mvz4yomp.fsf_-_-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2015-07-10 16:17 ` [REVIEW][PATCH 1/2] vfs: Commit to never having exectuables " Eric W. Biederman
2015-07-10 16:18 ` [REVIEW][PATCH 2/2] mnt: fs_fully_visible enforce noexec and nosuid if !SB_I_NOEXEC Eric W. Biederman
[not found] ` <87h9pcyokc.fsf_-_@x220.int.ebiederm.org>
[not found] ` <87h9pcyokc.fsf_-_-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2015-07-10 18:24 ` Richard Weinberger [this message]
[not found] ` <55A00DE9.7060806-/L3Ra7n9ekc@public.gmane.org>
2015-07-10 19:30 ` [REVIEW][PATCH 1/2] vfs: Commit to never having exectuables on proc and sysfs Greg Kroah-Hartman
[not found] ` <20150710193052.GB19824@kroah.com>
[not found] ` <20150710193052.GB19824-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2015-07-10 19:38 ` Richard Weinberger
[not found] ` <55A01F4B.9010205@nod.at>
[not found] ` <55A01F4B.9010205-/L3Ra7n9ekc@public.gmane.org>
2015-07-10 20:00 ` Eric W. Biederman
[not found] ` <87381eyz26.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2015-06-29 16:43 ` [GIT PULL] User namespace related fixes for v4.2 Linus Torvalds
2015-07-01 20:41 ` Eric W. Biederman
[not found] ` <878uazhapq.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2015-07-06 20:47 ` Seth Forshee
[not found] ` <20150706204748.GB22962@ubuntu-hedt>
2015-07-06 21:24 ` Eric W. Biederman
[not found] ` <E81DECCD-9B19-4D42-BE43-5987DE7B05DB@xmission.com>
[not found] ` <E81DECCD-9B19-4D42-BE43-5987DE7B05DB-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2015-07-06 22:25 ` Seth Forshee
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55A00DE9.7060806@nod.at \
--to=richard-/l3ra7n9ekc@public.gmane.org \
--cc=colona-nzgTgzXrdUbQT0dZR+AlfA@public.gmane.org \
--cc=containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org \
--cc=ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org \
--cc=gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org \
--cc=kenton-AuYgBwuPrUQTaNkGU808tA@public.gmane.org \
--cc=linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org \
--cc=mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
--cc=seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org \
--cc=tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
--cc=torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org \
--cc=viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).