Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 11 Nov 2010 10:07:13 +0100 | From | Ingo Molnar <> | Subject | Re: [Security] proactive defense: using read-only memory, RO/NX modules |
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* Kees Cook <kees.cook@canonical.com> wrote:
> Hi Ingo, > > On Wed, Nov 10, 2010 at 10:04:15AM +0100, Ingo Molnar wrote: > > * Kees Cook <kees.cook@canonical.com> wrote: > > > Oh, well, yes, that's a good reason. :) Where was this covered? I'd like to help > > > get it reproduced and ironed out. > > > > Matthieu Castet seems to have dusted off those patches and submitted two of them in > > this mail: > > > > Subject: [RFC] reworked NX protection for kernel data > > > > Matthieu, are you still interested in this topic? > > > > The original, broken patches were these -tip commits: > > > > 1e858c081af5: x86, mm: RO/NX protection for loadable kernel modules > > 18c60ddc9eff: x86, mm: NX protection for kernel data > > c226a2feba21: x86, mm: Set first MB as RW+NX > > b29d530510d4: x86, mm: Correcting improper large page preservation > > > > I reported one of the crashes in: > > > > Subject: Re: [tip:x86/mm] x86, mm: Set first MB as RW+NX > > > > on lkml. > > Thanks for looking this up! > > Can we get 1e858c081af5 and 18c60ddc9eff back in, and then work forward > from there?
Yeah. Please port them to latest -tip:
http://people.redhat.com/mingo/tip.git/README
And give them some testing, and send out the new series. I'll re-report the crash to you for a new kernel, if it still occurs.
(Please also keep Rusty and Linus Cc:-ed for the module bits.)
In hindsight, i think the kernel/module.c bits should be in arch/x86/kernel/module.c - the new code is full of x86 only names and facilities.
Also, please remove various checkpatch col80 artifacts, such as:
+ if (end_pfn > begin_pfn) + set_memory_nx(begin_pfn << PAGE_SHIFT, + end_pfn - begin_pfn);
that should be:
+ if (end_pfn > begin_pfn) + set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
Thanks,
Ingo
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