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From: Jiri Kosina <jikos@kernel.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: NeilBrown <neilb@suse.com>,
	kernel-hardening@lists.openwall.com,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC 0/4] make call_usermodehelper a bit more "safe"
Date: Tue, 20 Dec 2016 11:31:57 +0100 (CET)	[thread overview]
Message-ID: <alpine.LSU.2.20.1612201129320.19203@cbobk.fhfr.pm> (raw)
In-Reply-To: <alpine.LSU.2.20.1612201117220.19203@cbobk.fhfr.pm>

On Tue, 20 Dec 2016, Jiri Kosina wrote:

> I stay totally unconvinced that such kind of countermeasure brings any 
> value whatsoever. Could you please bring up a particular usecase, where 
> you have complete control over kernel memory, and still the only 
> possible exploit factor is redirecting usermodhelper? It feels like 
> rather random shot into darkness.

If we want to make usermod helper really secure, perhaps the best way to 
go would be to completely nuke it and handle everyhting in udev; that'd be 
quite some work though, especially so that we don't break all the corner 
cases of module autoloading (request_module() and such).

Thanks,

-- 
Jiri Kosina
SUSE Labs

  reply	other threads:[~2016-12-20 10:32 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-14 18:50 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
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 [this message]
2016-12-20 10:48             ` Greg KH

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