malloc_set_state and heap content

[Samuel Thibault]

Florian Weimer, on Wed 06 Jul 2016 22:36:05 +0200, wrote:
> On 07/06/2016 09:35 PM, Samuel Thibault wrote:
> >On Linux the space happens to be zero by luck, but with other kernels
> >that may not be true (it is not with the Hurd).
> 
> How gets Hurd away with that without introducing a security vulnerability?

What remains on the heap is initialization stuff, not remainders from
pages allocated by the kernel.

> >So I'd say we need the attached patch, don't we?
> 
> The patch does not address the issue because it does not alter the heap copy
> in existing Emacs binaries.  It would only become effective after
> recompiling Emacs.  Such recompiled Emacs binaries will no longer use the
> heap dumping mechanism.

Well, glibc is not only about emacs, is it? :)

Samuel