linux-kernel - Re: [2/3] mm: fix up some user-visible effects of the stack guard page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 5 Jan 2015 13:11:20 -0800
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Jay Foad <jay.foad@...il.com>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>
Subject: Re: [2/3] mm: fix up some user-visible effects of the stack guard page

On Mon, Jan 5, 2015 at 1:03 PM, Linus Torvalds
<torvalds@...ux-foundation.org> wrote:
>
> Yup, your analysis sounds correct.  My completely untested gut feel is
> that the problem is that we don't actually return the error from the
> expand_stack() call, so then do_anonymous_page() will allow the extra
> guard-page access.
>
> IOW, *maybe* a patch like this. TOTALLY UNTESTED! I may have missed
> something, and this may be complete crap.

.. and ti's still untested, but I'm pretty sure it's right - except we
should probably also allow an extra page for the stack rlimit (so that
the guard page doesn't count towards the limit).

                          Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/