From: David Laight <david.laight.linux@gmail.com>
To: Kees Cook <kees@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>,
Daniel Micay <danielmicay@gmail.com>,
Paul Moore <paul@paul-moore.com>,
linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/4] mm: security: Allow default HARDENED_USERCOPY to be set at compile time
Date: Thu, 23 Jan 2025 21:10:10 +0000 [thread overview]
Message-ID: <20250123211010.4ec97055@pumpkin> (raw)
In-Reply-To: <202501221651.3F5A6ACD@keescook>
...
> > +config HARDENED_USERCOPY_DEFAULT_ON
> > + bool "Harden memory copies by default"
> > + depends on HARDENED_USERCOPY
> > + default n
>
> This must be "default HARDENED_USERCOPY" or existing distro builds will
> break. All major distros enable this by default, and I don't want to
> risk HARDENED_USERCOPY_DEFAULT_ON getting missed and getting globally
> disabled.
It'll also cause grief for anyone trying to bisect.
Although that is always going to go wrong if it has been disabled.
I had 'fun' trying to locate a massive slowdown of a single threaded
program that was caused by a side effect of one of the speculative
execution mitigations getting enabled because the config parameter
got renamed.
David
next prev parent reply other threads:[~2025-01-23 21:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-22 17:19 [PATCH v2 0/4] Allow default HARDENED_USERCOPY to be set at compile time Mel Gorman
2025-01-22 17:19 ` [PATCH 1/4] mm: security: Move hardened usercopy under 'Kernel hardening options' Mel Gorman
2025-01-22 17:19 ` [PATCH 2/4] mm: security: Allow default HARDENED_USERCOPY to be set at compile time Mel Gorman
2025-01-23 0:57 ` Kees Cook
2025-01-23 11:37 ` Mel Gorman
2025-01-23 21:10 ` David Laight [this message]
2025-01-22 17:19 ` [PATCH 3/4] mm: security: Check early if HARDENED_USERCOPY is enabled Mel Gorman
2025-01-23 1:01 ` Kees Cook
2025-01-23 11:47 ` Mel Gorman
2025-01-22 17:19 ` [PATCH 4/4] fortify: Move FORTIFY_SOURCE under 'Kernel hardening options' Mel Gorman
2025-01-22 21:42 ` Paul Moore
2025-01-23 1:02 ` [PATCH v2 0/4] Allow default HARDENED_USERCOPY to be set at compile time Kees Cook
2025-01-23 11:49 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2025-01-23 22:11 [PATCH v3 " Mel Gorman
2025-01-23 22:11 ` [PATCH 2/4] mm: security: " Mel Gorman
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