Re: CVS commit: src/sys/arch

[Maxime Villard <max%m00nbsd.net@localhost>]

Le 24/11/2016 à 14:28, Masanobu SAITOH a écrit :
> Hi!
>
> On 2016/11/19 18:22, Maxime Villard wrote:
> > Module Name:	src
> > Committed By:	maxv
> > Date:		Sat Nov 19 09:22:04 UTC 2016
> >
> > Modified Files:
> > 	src/sys/arch/amd64/include: vmparam.h
> > 	src/sys/arch/i386/include: vmparam.h
> >
> > Log Message:
> > Put a one-page redzone between userland and the PTE space on amd64 and
> > i386.
> >
> > The PTE space is a critical region that maps the page tree, and bugs have
> > been found in both amd64 and i386 where the kernel would wrongly overflow
> > userland data on this area. This kind of bug is terrible, since it allows
> > userland to overwrite some entries of the page tree, which makes it easy
> > to patch the kernel text and get ring0 privileges.
> >
> >
> > To generate a diff of this commit:
> > cvs rdiff -u -r1.37 -r1.38 src/sys/arch/amd64/include/vmparam.h
> > cvs rdiff -u -r1.82 -r1.83 src/sys/arch/i386/include/vmparam.h
> >
> > Please note that diffs are not public domain; they are subject to the
> > copyright notices on the relevant files.
>
> My emacs dumps core with change.
>
> What should we do?

? It probably means there is some kind of stupid assumption or hack in
emacs. If you could send me the core, the binary and tell me which arch it
is, that would be nice. AFAICT, emacs is known to be buggy on netbsd.