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Date: Fri, 16 Feb 2024 11:28:46 -0800
From: Kees Cook <keescook@chromium.org>
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Luis Chamberlain <mcgrof@kernel.org>, linux-modules@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"linux-hardening @ vger . kernel . org" <linux-hardening@vger.kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v2] module: Don't ignore errors from set_memory_XX()
Message-ID: <202402161128.21EA3F8@keescook>
References: <21037bf38438a285f5dff9501668f1675bc45989.1708070781.git.christophe.leroy@csgroup.eu>
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In-Reply-To: <21037bf38438a285f5dff9501668f1675bc45989.1708070781.git.christophe.leroy@csgroup.eu>

On Fri, Feb 16, 2024 at 09:14:27AM +0100, Christophe Leroy wrote:
> set_memory_ro(), set_memory_nx(), set_memory_x() and other helpers
> can fail and return an error. In that case the memory might not be
> protected as expected and the module loading has to be aborted to
> avoid security issues.
> 
> Check return value of all calls to set_memory_XX() and handle
> error if any.
> 
> Add a check to not call set_memory_XX() on NULL pointers as some
> architectures may not like it allthough numpages is always 0 in that
> case. This also avoid a useless call to set_vm_flush_reset_perms().
> 
> Link: https://github.com/KSPP/linux/issues/7
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Yay! Glad to see this happening. Universal __must_check for set_memory_*()
starts to appear on the horizon. ;)

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

-- 
Kees Cook