Re: [PATCH] uts: Don't randomize "struct uts_namespace".

From: Kees Cook
Date: Fri Jul 06 2018 - 19:19:15 EST


On Fri, Jul 6, 2018 at 9:11 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Jul 6, 2018 at 3:07 AM Tetsuo Handa
> <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>> I noticed that makedumpfile utility is failing to check kernel version, for
>> it depends on offset of "struct uts_namespace"->name being sizeof(int).
>
> For something like this, we fix makedumpfile instead. This is not a
> "user program" using system calls etc, this is something that delves
> into the kernel dump and tries to make sense of it.
>
> Where is the makedumpfile source code? What is it trying to do, and why?
>
> One option is to just say "hey, you can't make much sense of a
> randomized kernel dump anyway, so don't even try".

I would second this -- trying to deal with a randomized layout kernel
dump is going to be much worse than just looking at uts_namespace. :)

-Kees

--
Kees Cook
Pixel Security