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Date: Thu, 30 Jul 2026 13:35:44 +0200
From: Lukas Wunner <lukas@wunner.de>
To: Changwei Zou <changwei.zou@canonical.com>
Cc: Martin.Kepplinger-Novakovic@ginzinger.com, davem@davemloft.net,
	herbert@gondor.apana.org.au, ignat@linux.win,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	martink@posteo.de
Subject: Re: [PATCH v4] crypto: rsassa-pkcs1 - Avoid cacheline sharing with
 underlying driver
Message-ID: <ams3ED05SiobrDap@wunner.de>
References: <20260730112026.1612066-1-changwei.zou@canonical.com>
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In-Reply-To: <20260730112026.1612066-1-changwei.zou@canonical.com>

On Thu, Jul 30, 2026 at 09:20:26PM +1000, Changwei Zou wrote:
> +++ b/crypto/rsassa-pkcs1.c
> @@ -227,6 +227,7 @@ static int rsassa_pkcs1_verify(struct crypto_sig *tfm,
>  	struct scatterlist sg;
>  	unsigned int dst_len;
>  	unsigned int pos;
> +	u8 *key_buf __free(kfree_sensitive) = NULL;
>  	u8 *out_buf;
>  	int err;
>

Hm, why use an additional key_buf variable instead of using the existing
out_buf?

key_buf also seems to be misnomer, the buffer contains a digest.

For neatness, could you move the new declaration up below the one for
child_req so that the variable declarations sort of adhere to inverse
christmas tree convention.

Thanks,

Lukas