From: Florian Weimer <fw@deneb.enyo.de>
To: Sasha Levin <sashal@kernel.org>
Cc: corbet@lwn.net, akpm@linux-foundation.org,
skhan@linuxfoundation.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
gregkh@linuxfoundation.org
Subject: Re: [PATCH v2] killswitch: add per-function short-circuit mitigation primitive
Date: Sat, 09 May 2026 14:02:24 +0200 [thread overview]
Message-ID: <87ecjku6y7.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <20260508195749.1885522-1-sashal@kernel.org> (Sasha Levin's message of "Fri, 8 May 2026 15:57:48 -0400")
* Sasha Levin:
> When a kernel (security) issue goes public, fleets stay exposed until a patched
> kernel is built, distributed, and rebooted into.
>
> For many such issues the simplest mitigation is to stop calling the buggy
> function. Killswitch provides that. An admin writes:
>
> echo "engage af_alg_sendmsg -1" \
> > /sys/kernel/security/killswitch/control
>
> After this, af_alg_sendmsg() returns -EPERM on every call without
> running its body. The mitigation takes effect immediately, and is dropped on
> the next reboot -- by which point a patched kernel is hopefully in place.
Do you expect this to be safe to enable in kernel lockdown mode (i.e.,
with typical Secure Boot configurations in distributions)?
next prev parent reply other threads:[~2026-05-09 12:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-08 19:57 [PATCH v2] killswitch: add per-function short-circuit mitigation primitive Sasha Levin
2026-05-09 12:02 ` Florian Weimer [this message]
2026-05-09 12:34 ` Sasha Levin
2026-05-11 10:33 ` Anthony Iliopoulos
2026-05-11 11:15 ` Sasha Levin
2026-05-11 17:23 ` Anthony Iliopoulos
2026-05-11 20:12 ` Sasha Levin
2026-05-11 13:14 ` Breno Leitao
2026-05-11 13:41 ` Sasha Levin
2026-05-11 14:59 ` Breno Leitao
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