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Date: Fri, 9 Feb 2024 16:19:14 -0800
From: Kees Cook <keescook@chromium.org>
To: Erick Archer <erick.archer@gmx.com>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
	Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH] irqchip/bcm-6345-l1: Prefer struct_size over open coded
 arithmetic
Message-ID: <202402091619.80D0AE3141@keescook>
References: <20240209181600.9472-1-erick.archer@gmx.com>
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In-Reply-To: <20240209181600.9472-1-erick.archer@gmx.com>

On Fri, Feb 09, 2024 at 07:16:00PM +0100, Erick Archer wrote:
> This is an effort to get rid of all multiplications from allocation
> functions in order to prevent integer overflows [1].
> 
> As the cpu variable is a pointer to "struct bcm6345_l1_cpu" and this
> structure ends in a flexible array:
> 
> struct bcm6345_l1_cpu {
> 	[...]
> 	u32	enable_cache[];
> };
> 
> the preferred way in the kernel is to use the struct_size() helper to
> do the arithmetic instead of the argument "size + count * size" in the
> kzalloc() function.
> 
> This way, the code is more readable and more safer.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
> Link: https://github.com/KSPP/linux/issues/162 [2]
> Signed-off-by: Erick Archer <erick.archer@gmx.com>

Thanks!

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

-- 
Kees Cook