Re: [git head] X86_PAT & mprotect

[Hugh Dickins]

On Fri, 9 May 2008, Venki Pallipadi wrote:
> 
> There is a defect in mprotect, which lets the user to change the page
> cache type bits by-passing the kernel reserve_memtype and free_memtype
> wrappers. Fix the problem by not letting mprotect change the PAT bits.
> 
> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
> Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
> Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>

Thanks a lot for finalizing that, Venki: looks good to me.
I didn't originally sign-off my version of your patch, but am happy
to do so now that you've gone over it again and fixed the pte_modify
issue (though I'm not sure what the order of our signoffs should be).

I shall need to cover the MAP_PRIVATE COW issue in do_wp_page,
but I think that's better done as a separate patch: I'll attend
to it in a few days, it's not something that will upset anyone
bisecting, my mind is elsewhere at present.

Hugh
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