On Wed, Dec 6, 2017 at 3:21 PM, Kees Cook [off-list ref] wrote:

On Wed, Dec 6, 2017 at 2:31 AM, David Laight [off-list ref] wrote:

quoted

I can also image issues where you want to know whether 2 pointers point
into the same structure (like an skb).

This is already retained due to the hashing. i.e. the same pointer
value will produce the same hash value, so that kind of direct
comparison still works.

DavidL isn't talking about the _same_ pointer, he's talking about it
being offset from the same base.

But realistically, I don't think we ever hash things like that anyway.

Things like that do show up in register dumps etc during oopses, but
those aren't hashed.

            Linus