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From: Kees Cook <keescook@chromium.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux@armlinux.org.uk, linus.walleij@linaro.org, arnd@arndb.de,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ARM: decompressor: disable stack protector
Date: Tue, 26 Oct 2021 10:14:36 -0700	[thread overview]
Message-ID: <202110261013.7A0CE6D71@keescook> (raw)
In-Reply-To: <20211026082752.3519140-1-ardb@kernel.org>

On Tue, Oct 26, 2021 at 10:27:52AM +0200, Ard Biesheuvel wrote:
> Enabling the stack protector in the decompressor is of dubious value,
> given that it uses a fixed value for the canary, cannot print any output
> unless CONFIG_DEBUG_LL is enabled (which relies on board specific build
> time settings), and is already disabled for a good chunk of the code
> (libfdt).
> 
> So let's just disable it in the decompressor. This will make it easier
> in the future to manage the command line options that would need to be
> removed again in this context for the TLS register based stack
> protector.
> 
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Yeah, that's fine. There's no good reason to complicate the decompressor
for the stack protector. If someone is trying to exploit the kernel at
this stage, the system has a much bigger problem. ;)

Acked-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

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  reply	other threads:[~2021-10-26 17:16 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-26  8:27 [PATCH] ARM: decompressor: disable stack protector Ard Biesheuvel
2021-10-26 17:14 ` Kees Cook [this message]
2021-10-26 17:58 ` Linus Walleij

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