From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: LKML <linux-kernel@vger.kernel.org>, kernel-hardening@lists.openwall.com
Subject: Re: [kernel-hardening] [RFC 0/4] make call_usermodehelper a bit more "safe"
Date: Wed, 14 Dec 2016 15:16:29 -0800 [thread overview]
Message-ID: <20161214231629.GA23558@kroah.com> (raw)
In-Reply-To: <CAHmME9pq=1hZirN6uwM5Tgrp5iG5mqmXw37gQYxFzcJ4Kkj9dQ@mail.gmail.com>
On Wed, Dec 14, 2016 at 10:28:18PM +0100, Jason A. Donenfeld wrote:
> Hi Greg,
>
> On Wed, Dec 14, 2016 at 7:50 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> > So, anyone have any better ideas? Is this approach worth it? Or should
> > we just go down the "whitelist" path?
>
> I think your approach is generally better than the whitelist path. But
> maybe there's yet a third approach that involves futzing with page
> permissions at runtime. I think grsec does something similar with
> read_mostly function pointer structs. Namely, they make them read-only
> const, and then temporarily twiddle the page permissions if it needs
> to be changed while disabling preemption. There could be a particular
> class of data that needs to be "opened" and "closed" in order to
> modify. Seems like these strings would be a good use of that.
Yes, but that's a much larger issue and if that feature ever lands, we
can switch these strings over to that functionality.
thanks,
greg k-h
next prev parent reply other threads:[~2016-12-14 23:16 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-14 18:50 [RFC 0/4] make call_usermodehelper a bit more "safe" Greg KH
2016-12-14 18:50 ` [PATCH 1/4] kmod: make usermodehelper path a const string Greg KH
2016-12-14 18:50 ` [PATCH 2/4] drbd: rename "usermode_helper" to "drbd_usermode_helper" Greg KH
2016-12-14 18:50 ` [PATCH 3/4] Make static usermode helper binaries constant Greg KH
2016-12-14 19:11 ` [kernel-hardening] " Greg KH
2016-12-14 20:29 ` Rich Felker
2016-12-14 20:54 ` Greg KH
2016-12-15 17:54 ` Greg KH
2016-12-15 20:51 ` Daniel Micay
2016-12-15 21:18 ` Greg KH
2016-12-16 0:05 ` Daniel Micay
2016-12-16 0:14 ` Daniel Micay
2016-12-14 18:51 ` [RFC 4/4] Introduce CONFIG_READONLY_USERMODEHELPER Greg KH
2016-12-14 20:31 ` Kees Cook
2016-12-14 20:57 ` Greg KH
2016-12-14 19:25 ` [kernel-hardening] [RFC 0/4] make call_usermodehelper a bit more "safe" Mark Rutland
2016-12-14 20:16 ` Kees Cook
2016-12-14 21:28 ` Jason A. Donenfeld
2016-12-14 23:16 ` Greg Kroah-Hartman [this message]
2016-12-16 1:02 ` NeilBrown
2016-12-16 12:49 ` Greg KH
2016-12-19 13:34 ` Jiri Kosina
2016-12-20 9:27 ` Greg KH
2016-12-20 10:27 ` Jiri Kosina
2016-12-20 10:31 ` Jiri Kosina
2016-12-20 10:48 ` Greg KH
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