crypto: stm32 - fix loop iterating through scatterlist for DMA

commit d9c83f71eeceed2cb54bb78be84f2d4055fd9a1f upstream.

We were reading the length of the scatterlist sg after copying value of
tsg inside.
So we are using the size of the previous scatterlist and for the first
one we are using an unitialised value.
Fix this by copying tsg in sg[0] before reading the size.

Fixes : 8a1012d3f2ab ("crypto: stm32 - Support for STM32 HASH module")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Bourgoin <thomas.bourgoin@foss.st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/crypto/stm32/stm32-hash.c b/drivers/crypto/stm32/stm32-hash.c
index 342ed46ddf8828c30c0adca69c692a7ab867b0ea..9760fca94eb55c6f88ec7118db1d1ae53db03511 100644 (file)
--- a/drivers/crypto/stm32/stm32-hash.c
+++ b/drivers/crypto/stm32/stm32-hash.c
@@ -627,9 +627,9 @@ static int stm32_hash_dma_send(struct stm32_hash_dev *hdev)
        }
 
        for_each_sg(rctx->sg, tsg, rctx->nents, i) {
+               sg[0] = *tsg;
                len = sg->length;
 
-               sg[0] = *tsg;
                if (sg_is_last(sg)) {
                        if (hdev->dma_mode == 1) {
                                len = (ALIGN(sg->length, 16) - 16);