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Date: Wed, 28 Feb 2024 14:41:48 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Vinod Koul
 <vkoul@kernel.org>, Linus Walleij <linus.walleij@linaro.org>, Jonathan
 Cameron <Jonathan.Cameron@huawei.com>, Mark Brown <broonie@kernel.org>,
 linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
 linux-spi@vger.kernel.org, netdev@vger.kernel.org,
 linux-hardening@vger.kernel.org, Jonathan Cameron <jic23@kernel.org>,
 Lars-Peter Clausen <lars@metafoo.de>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Paolo Abeni
 <pabeni@redhat.com>, "Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: Re: [PATCH v4 7/8] net-device: Use new helpers from overflow.h in
 netdevice APIs
Message-ID: <20240228144148.5c227487@kernel.org>
In-Reply-To: <202402281341.AC67EB6E35@keescook>
References: <20240228204919.3680786-1-andriy.shevchenko@linux.intel.com>
	<20240228204919.3680786-8-andriy.shevchenko@linux.intel.com>
	<202402281341.AC67EB6E35@keescook>
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On Wed, 28 Feb 2024 13:46:10 -0800 Kees Cook wrote:
> I really don't like hiding these trailing allocations from the compiler.
> Why can't something like this be done (totally untested):
> 
> 
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 118c40258d07..dae6df4fb177 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -2475,6 +2475,8 @@ struct net_device {
>  	/** @page_pools: page pools created for this netdevice */
>  	struct hlist_head	page_pools;
>  #endif
> +	u32			priv_size;
> +	u8			priv_data[] __counted_by(priv_size) __aligned(NETDEV_ALIGN);

I like, FWIW, please submit! :)