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From:   Corentin Labbe <clabbe@baylibre.com>
To:     arnd@arndb.de, davem@davemloft.net, herbert@gondor.apana.org.au,
        jernej.skrabec@siol.net, mripard@kernel.org, wens@csie.org
Cc:     linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com,
        Corentin Labbe <clabbe@baylibre.com>, stable@vger.kernel.org
Subject: [PATCH v4 2/8] crypto: sun4i-ss: checking sg length is not sufficient
Date:   Mon, 14 Dec 2020 20:02:26 +0000
Message-Id: <20201214200232.17357-3-clabbe@baylibre.com>
In-Reply-To: <20201214200232.17357-1-clabbe@baylibre.com>
References: <20201214200232.17357-1-clabbe@baylibre.com>
Precedence: bulk

The optimized cipher function need length multiple of 4 bytes.
But it get sometimes odd length.
This is due to SG data could be stored with an offset.

So the fix is to check also if the offset is aligned with 4 bytes.
Fixes: 6298e948215f2 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Cc: <stable@vger.kernel.org>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
 drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
index 19f1aa577ed4..f49797588329 100644
--- a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
@@ -186,12 +186,12 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 	 * we can use the SS optimized function
 	 */
 	while (in_sg && no_chunk == 1) {
-		if (in_sg->length % 4)
+		if ((in_sg->length | in_sg->offset) & 3u)
 			no_chunk = 0;
 		in_sg = sg_next(in_sg);
 	}
 	while (out_sg && no_chunk == 1) {
-		if (out_sg->length % 4)
+		if ((out_sg->length | out_sg->offset) & 3u)
 			no_chunk = 0;
 		out_sg = sg_next(out_sg);
 	}
-- 
2.26.2