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 14:54:57 -0700 [thread overview]
Message-ID: <202103311453.A840B7FC5@keescook> (raw)
In-Reply-To: <87im5769op.ffs@nanos.tec.linutronix.de>
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.
> Other than that.
>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Thank you for the reviews!
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...)
--
Kees Cook
WARNING: multiple messages have this Message-ID (diff)
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 14:54:57 -0700 [thread overview]
Message-ID: <202103311453.A840B7FC5@keescook> (raw)
In-Reply-To: <87im5769op.ffs@nanos.tec.linutronix.de>
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.
> Other than that.
>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Thank you for the reviews!
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...)
--
Kees Cook
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-03-31 21:55 UTC|newest]
Thread overview: 41+ 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 ` 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 ` Kees Cook
2021-03-30 20:57 ` [PATCH v8 2/6] init_on_alloc: Optimize static branches Kees Cook
2021-03-30 20:57 ` Kees Cook
2021-03-30 20:57 ` [PATCH v8 3/6] stack: Optionally randomize kernel stack offset each syscall Kees Cook
2021-03-30 20:57 ` Kees Cook
2021-03-31 7:53 ` Thomas Gleixner
2021-03-31 7:53 ` Thomas Gleixner
2021-03-31 21:54 ` Kees Cook [this message]
2021-03-31 21:54 ` Kees Cook
2021-03-31 22:38 ` Thomas Gleixner
2021-03-31 22:38 ` Thomas Gleixner
2021-04-01 6:31 ` Kees Cook
2021-04-01 6:31 ` Kees Cook
2021-04-01 8:30 ` Will Deacon
2021-04-01 8:30 ` Will Deacon
2021-04-01 11:15 ` David Laight
2021-04-01 11:15 ` David Laight
2021-04-01 11:15 ` David Laight
2021-04-01 22:42 ` Kees Cook
2021-04-01 22:42 ` Kees Cook
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
2021-03-30 20:57 ` Kees Cook
2021-03-31 7:50 ` Thomas Gleixner
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 ` Kees Cook
2021-03-30 20:57 ` [PATCH v8 6/6] lkdtm: Add REPORT_STACK for checking stack offsets Kees Cook
2021-03-30 20:57 ` Kees Cook
2021-04-01 19:17 ` [PATCH] Where we are for this patch? Roy Yang
2021-04-01 19:17 ` Roy Yang
2021-04-01 19:17 ` Roy Yang
2021-04-01 19:48 ` Al Viro
2021-04-01 19:48 ` Al Viro
2021-04-01 20:13 ` Theodore Ts'o
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
2021-04-01 21:46 ` 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=202103311453.A840B7FC5@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.