From: Dave Hansen <dave.hansen@intel.com>
To: s1nkhole <dedemorow@gmail.com>
Cc: x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
hpa@zytor.com, Peter Zijlstra <peterz@infradead.org>,
Kees Cook <kees@kernel.org>, Brian Gerst <brgerst@gmail.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/entry/32: Harden return-to-user
Date: Wed, 28 Oct 2026 13:50:59 -0700 [thread overview]
Message-ID: <3d982c1c-4c97-4dbc-958a-4e71131c0020@intel.com> (raw)
In-Reply-To: <20261028192139.32606-1-dedemorow@gmail.com>
On 10/28/26 12:21, s1nkhole wrote:
> If you have a moment: this is my first work on arch/x86, and I would like
> to contribute something that is actually useful. Is there a small task
> in x86/entry or in kernel hardening that you would suggest as a better
> starting point, or a place where help with testing or review would be
> welcome? I can build and run kernels under QEMU.
It's not small, but kernel shadow stacks are an _incredibly_ powerful
hardening tool. You can buy a system off the shelf that sanely supports
them (including FRED), but the kernel doesn't support them yet.
My current work in progress is here:
> https://git.kernel.org/pub/scm/linux/kernel/git/daveh/devel.git/log/?h=kss-2026-10-23
Another set of eyes on that would be nice. Although I do think I'm going
to abandon tacking the shadow stack on to the thread_union for now. So I
don't suggest looking at it too deeply until I get another version out
the door.
One thing you could do today is go into the list in here:
> https://git.kernel.org/pub/scm/linux/kernel/git/daveh/devel.git/commit/?h=kss-2026-10-21&id=4dab5fe58904ee07b3622f25bbe3c1b7ff820bf5
and pick a feature or two and figure out if they need fixing for shadow
stacks or not, and if so what a fix might look like.
Or another set of eyes on this:
> https://git.kernel.org/pub/scm/linux/kernel/git/daveh/devel.git/log/?h=taskfun-2026-10-26
It's ready to post but I'm just waiting for the merge window to close.
prev parent reply other threads:[~2026-10-28 20:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-27 21:52 Andrey Zakharov
2026-10-27 22:01 ` Dave Hansen
2026-10-28 19:21 ` s1nkhole
2026-10-28 20:40 ` Borislav Petkov
2026-10-28 20:50 ` Dave Hansen [this message]
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