Hi Andy, On Fri, Apr 24, 2015 at 5:10 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > Even though I've been accused (correctly?) of suggesting that, I'm not > sure I like it anymore. Suppose I map some anonymous memory, learn > its (scrambled) pfn, then unmap it and remap a setuid file. Now I can > tell whether I've mapped the setuid file at the same pfn that was > mapped as my anonymous memory. IIRC that's sufficient for one of the > variants of Mark's attack. In fairness, you may have mentioned it but it's entirely possible you didn't originate the suggestion and I quoted out of context. Sorry for implicating you ;-) That's an attack that I hadn't considered when thinking about this stuff. Zeroing the page frame numbers is an easier patch, so arguments in favour of that are a happy answer as far as I'm concerned! Thanks, Mark -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
