From: Pavel Machek <pavel@ucw.cz>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>, Rik van Riel <riel@redhat.com>,
David Rientjes <rientjes@google.com>,
Aaron Tomlin <atomlin@redhat.com>,
Dario Faggioli <raistlin@linux.it>,
Andi Kleen <ak@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>, Jens Axboe <axboe@fb.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Paul Wise <pabs3@bonedaddy.net>
Subject: Re: [PATCH] sysctl: terminate strings also on \r
Date: Mon, 27 Oct 2014 10:56:26 +0100 [thread overview]
Message-ID: <20141027095626.GD9807@amd> (raw)
In-Reply-To: <CAGXu5j+sW89tZDA5GQnkL4E9wHTScftyxUhyAjbWnEfxGocBjg@mail.gmail.com>
On Wed 2014-10-22 16:43:10, Kees Cook wrote:
> On Wed, Oct 22, 2014 at 4:26 PM, Andrew Morton
> <akpm@linux-foundation.org> wrote:
> > On Tue, 21 Oct 2014 13:21:37 -0700 Kees Cook <keescook@chromium.org> wrote:
> >
> >> From: Paul Wise <pabs3@bonedaddy.net>
> >>
> >> This partially mitigates a common strategy used by attackers for hiding
> >> the full contents of strings in procfs from naive sysadmins who use cat,
> >> more or sysctl to inspect the contents of strings in procfs.
> >>
> >> ...
> >>
> >> --- a/kernel/sysctl.c
> >> +++ b/kernel/sysctl.c
> >> @@ -1739,7 +1739,7 @@ static int _proc_do_string(char *data, int maxlen, int write,
> >> while ((p - buffer) < *lenp && len < maxlen - 1) {
> >> if (get_user(c, p++))
> >> return -EFAULT;
> >> - if (c == 0 || c == '\n')
> >> + if (c == 0 || c == '\n' || c == '\r')
> >> break;
> >> data[len++] = c;
> >> }
> >
> > There are no valid uses of \r in a procfs write?
>
> I struggle to imagine one; everything I found that uses proc_dostring
> seems to be names, paths, and commands.
Well, filename can contain \r, right?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2014-10-27 9:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-21 20:21 [PATCH] sysctl: terminate strings also on \r Kees Cook
2014-10-22 10:03 ` Aaron Tomlin
2014-10-22 13:39 ` Paul E. McKenney
2014-10-22 22:49 ` David Rientjes
2014-10-22 23:26 ` Andrew Morton
2014-10-22 23:43 ` Kees Cook
2014-10-23 2:00 ` Andrew Morton
2014-10-23 16:39 ` Kees Cook
2014-10-23 18:23 ` Andrew Morton
2014-10-23 18:50 ` Kees Cook
2014-10-27 9:56 ` Pavel Machek [this message]
2014-10-27 10:11 ` Geert Uytterhoeven
2014-10-27 12:01 ` Pavel Machek
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=20141027095626.GD9807@amd \
--to=pavel@ucw.cz \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=atomlin@redhat.com \
--cc=axboe@fb.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=pabs3@bonedaddy.net \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=raistlin@linux.it \
--cc=riel@redhat.com \
--cc=rientjes@google.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.