From: Kees Cook <keescook@chromium.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Elena Reshetova <elena.reshetova@intel.com>,
x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Potapenko <glider@google.com>,
Alexander Popov <alex.popov@linux.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jann Horn <jannh@google.com>, Vlastimil Babka <vbabka@suse.cz>,
David Hildenbrand <david@redhat.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jonathan Corbet <corbet@lwn.net>,
Randy Dunlap <rdunlap@infradead.org>,
kernel-hardening@lists.openwall.com,
linux-hardening@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 3/6] stack: Optionally randomize kernel stack offset each syscall
Date: Wed, 31 Mar 2021 23:31:39 -0700 [thread overview]
Message-ID: <202103312329.394CCA13CF@keescook> (raw)
In-Reply-To: <87v9973q54.ffs@nanos.tec.linutronix.de>
On Thu, Apr 01, 2021 at 12:38:31AM +0200, Thomas Gleixner wrote:
> On Wed, Mar 31 2021 at 14:54, Kees Cook wrote:
> > On Wed, Mar 31, 2021 at 09:53:26AM +0200, Thomas Gleixner wrote:
> >> On Tue, Mar 30 2021 at 13:57, Kees Cook wrote:
> >> > +/*
> >> > + * Do not use this anywhere else in the kernel. This is used here because
> >> > + * it provides an arch-agnostic way to grow the stack with correct
> >> > + * alignment. Also, since this use is being explicitly masked to a max of
> >> > + * 10 bits, stack-clash style attacks are unlikely. For more details see
> >> > + * "VLAs" in Documentation/process/deprecated.rst
> >> > + * The asm statement is designed to convince the compiler to keep the
> >> > + * allocation around even after "ptr" goes out of scope.
> >>
> >> Nit. That explanation of "ptr" might be better placed right at the
> >> add_random...() macro.
> >
> > Ah, yes! Fixed in v9.
>
> Hmm, looking at V9 the "ptr" thing got lost ....
I put the comment inline in the macro directly above the asm().
> > Do you want to take this via -tip (and leave off the arm64 patch until
> > it is acked), or would you rather it go via arm64? (I've sent v9 now...)
>
> Either way is fine.
Since the arm64 folks have been a bit busy, can you just put this in
-tip and leave off the arm64 patch for now?
Thanks!
--
Kees Cook
next prev parent reply other threads:[~2021-04-01 6:32 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 20:57 [PATCH v8 0/6] Optionally randomize kernel stack offset each syscall Kees Cook
2021-03-30 20:57 ` [PATCH v8 1/6] jump_label: Provide CONFIG-driven build state defaults Kees Cook
2021-03-30 20:57 ` [PATCH v8 2/6] init_on_alloc: Optimize static branches Kees Cook
2021-03-30 20:57 ` [PATCH v8 3/6] stack: Optionally randomize kernel stack offset each syscall Kees Cook
2021-03-31 7:53 ` Thomas Gleixner
2021-03-31 21:54 ` Kees Cook
2021-03-31 22:38 ` Thomas Gleixner
2021-04-01 6:31 ` Kees Cook [this message]
2021-04-01 8:30 ` Will Deacon
2021-04-01 11:15 ` David Laight
2021-04-01 22:42 ` Kees Cook
2021-03-30 20:57 ` [PATCH v8 4/6] x86/entry: Enable random_kstack_offset support Kees Cook
2021-03-31 7:50 ` Thomas Gleixner
2021-03-30 20:57 ` [PATCH v8 5/6] arm64: entry: " Kees Cook
2021-03-30 20:57 ` [PATCH v8 6/6] lkdtm: Add REPORT_STACK for checking stack offsets Kees Cook
2021-04-01 19:17 ` [PATCH] Where we are for this patch? Roy Yang
2021-04-01 19:48 ` Al Viro
2021-04-01 20:13 ` Theodore Ts'o
2021-04-01 21:46 ` [PATCH v8 0/6] Optionally randomize kernel stack offset each syscall Kees Cook
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=202103312329.394CCA13CF@keescook \
--to=keescook@chromium.org \
--cc=akpm@linux-foundation.org \
--cc=alex.popov@linux.com \
--cc=ard.biesheuvel@linaro.org \
--cc=catalin.marinas@arm.com \
--cc=corbet@lwn.net \
--cc=david@redhat.com \
--cc=elena.reshetova@intel.com \
--cc=glider@google.com \
--cc=jannh@google.com \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=rppt@linux.ibm.com \
--cc=tglx@linutronix.de \
--cc=vbabka@suse.cz \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).