Messages in this thread |  | | Date | Wed, 15 Nov 2000 22:16:39 -0800 | From | "H. Peter Anvin" <> | Subject | Re: Modprobe local root exploit |
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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
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