Messages in this thread | | | From | Kees Cook <> | Date | Tue, 3 Jan 2017 15:19:26 -0800 | Subject | Re: [PATCH] sgi-xp: use designated initializers |
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On Wed, Dec 21, 2016 at 8:24 AM, Robin Holt <robinmholt@gmail.com> wrote: > On Fri, Dec 16, 2016 at 7:01 PM, Kees Cook <keescook@chromium.org> wrote: >> Prepare to mark sensitive kernel structures for randomization by making >> sure they're using designated initializers. These were identified during >> allyesconfig builds of x86, arm, and arm64, with most initializer fixes >> extracted from grsecurity. > > I guess I don't understand the context enough here to give you a > Signed-off-by. Can you give us more background on this randomization?
Sure thing! The randomization is on the order of function pointers in all-pointer structures (like struct xpc_interface). As long as the memory containing the structure isn't shared externally, this randomization should have no operational effect. The reason explicit no-op functions were added was to avoid ugly casts, etc.
> From what I see in the code here, I can see you are providing > equivalent functionality and I would give it a signed-off-by, but I am > not sure this randomization of which you speak is not going to cause > problems for XP, XPC, XPNET, and XPMEM (out of tree GPL kernel > module).
Ah, hm, does this module share the structure without being built against the kernel? (If built with the kernel, the randomization plugin will keep things in the right order.)
-Kees
-- Kees Cook Nexus Security
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