lkml.org 
[lkml]   [2000]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Modprobe local root exploit
Keith Owens wrote:
>
> On 15 Nov 2000 22:04:47 -0800,
> "H. Peter Anvin" <hpa@zytor.com> wrote:
> >No, it's correct, actually, but probably not what you want. It will
> >include all letters [A-Za-z], but if a module named "ärlig"...
>
> Trying to sanitise the module name in request_module is the wrong fix
> anyway, the kernel can ask for any module name it likes. What it must
> not do is treat user supplied input _unchanged_ as a module name.
>
> modutils 2.3.20 (just released) fixes all the known local root
> exploits, without kernel changes. However 2.3.20 does nothing about
> this problem: "ping6 -I module_name" which lets any user load any
> module. That problem exists because the kernel passes user supplied
> data unchanged to request_module. The only fix is to add a prefix to
> user supplied input (say 'user-interface-') before passing the text to
> request_module. This has to be fixed in the higher layers of the
> kernel, it cannot be fixed in request_module or modprobe.
>

Sure, but if you have to change the kernel anyway you ought to pass the
"--" option so modprobe knows that regardless what the string is, it's a
module name and not an option.

-hpa

--
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:45    [W:0.041 / U:0.420 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site