Messages in this thread |  | | | Date | Fri, 27 May 2011 19:46:44 +0200 | | From | Ingo Molnar <> | | Subject | Re: [RFC][PATCH] Randomize kernel base address on boot |
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* Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Fri, May 27, 2011 at 10:16 AM, Ingo Molnar <mingo@elte.hu> wrote: > > > > Well, 'fixing the info leaks' will obfuscate previously useful files > > such as /proc/kallsyms ... > > Guys, stop with the crazy already. > > YOU HAVE TO DO THAT FOR THE LINK-TIME-OBFUSCATION TOO! > > > That's one of the advantages of randomization: it allows us to > > expose RIPs without them being an instant information leak. > > Except you clearly aren't thinking that through AT ALL. > > The obfuscation of things like /proc/kallsyms is *exactly*the*same* > whether you do the randomization at boot-time or install-time.
Well, but two mails ago you said:
> And load-time randomization has all these nasty problems with > memory maps etc, because we obviously have to shift the whole > kernel around by some fixed offset. But if there was some way to > just re-link the distro kernel easily, then it could be done by the > kernel install scripts, and it could potentially do more than just > "shift up load address by some random number".
If i understood you correctly you suggest randomizing the image by shifting the symbols in it around. The boot loader would still load an 'image' where it always loads it - just that image itself is randomized internally somewhat, right?
( because that's the only way we can avoid the problems with e820 memory maps which you referred to, if don't actually change the load address. )
Have i understood you correctly?
Thanks,
Ingo
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