Re: next-20170515: WARNING: CPU: 0 PID: 1 at arch/x86/mm/dump_pagetables.c:236 note_page+0x630/0x7e0

From: Kees Cook
Date: Fri May 19 2017 - 15:16:35 EST

On Fri, May 19, 2017 at 11:27 AM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> One thing I've pondered: can we make some debugging mode (kmemleak,
> perhaps?) check that freed memory is RW at the time it's freed? I
> once wrote some buggy code that freed an R page and caused an OOPS
> much later, and this bug here seems likely to be some code that frees
> RWX memory.

Which begs for even more checks: nothing should ever make a page RWX.
Either R, RW, or RX only... (or X too I guess, in the future).


Kees Cook
Pixel Security