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From:   Corentin Labbe <clabbe@baylibre.com>
To:     arnd@arndb.de, davem@davemloft.net, herbert@gondor.apana.org.au,
        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>
Subject: [PATCH 1/7] crypto: sun4i-ss: linearize buffers content must be kept
Date:   Thu, 17 Sep 2020 18:35:52 +0000
Message-Id: <1600367758-28589-2-git-send-email-clabbe@baylibre.com>
In-Reply-To: <1600367758-28589-1-git-send-email-clabbe@baylibre.com>
References: <1600367758-28589-1-git-send-email-clabbe@baylibre.com>
Precedence: bulk

When running the non-optimized cipher function, SS produce partial random
output.
This is due to linearize buffers being reseted after each loop.

Fixes: 8d3bcb9900ca ("crypto: sun4i-ss - reduce stack usage")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
 drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
index b72de8939497..b92d175b5d2a 100644
--- a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
@@ -163,6 +163,8 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 	unsigned int todo;
 	struct sg_mapping_iter mi, mo;
 	unsigned int oi, oo;	/* offset for in and out */
+	char buf[4 * SS_RX_MAX];/* buffer for linearize SG src */
+	char bufo[4 * SS_TX_MAX]; /* buffer for linearize SG dst */
 	unsigned int ob = 0;	/* offset in buf */
 	unsigned int obo = 0;	/* offset in bufo*/
 	unsigned int obl = 0;	/* length of data in bufo */
@@ -233,8 +235,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 
 	while (oleft) {
 		if (ileft) {
-			char buf[4 * SS_RX_MAX];/* buffer for linearize SG src */
-
 			/*
 			 * todo is the number of consecutive 4byte word that we
 			 * can read from current SG
@@ -295,8 +295,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 				oo = 0;
 			}
 		} else {
-			char bufo[4 * SS_TX_MAX]; /* buffer for linearize SG dst */
-
 			/*
 			 * read obl bytes in bufo, we read at maximum for
 			 * emptying the device
-- 
2.26.2