crypto: ccree - unmap buffer before copying IV

commit c139c72e2beb3e3db5148910b3962b7322e24374 upstream.

We were copying the last ciphertext block into the IV field
for CBC before removing the DMA mapping of the output buffer
with the result of the buffer sometime being out-of-sync cache
wise and were getting intermittent cases of bad output IV.

Fix it by moving the DMA buffer unmapping before the copy.
Signed-off-by: NGilad Ben-Yossef <gilad@benyossef.com>
Fixes: 00904aa0 ("crypto: ccree - fix iv handling")
Cc: <stable@vger.kernel.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/crypto/ccree/cc_cipher.c

@@ -635,6 +635,8 @@ static void cc_cipher_complete(struct device *dev, void *cc_req, int err)
 	unsigned int ivsize = crypto_skcipher_ivsize(sk_tfm);
 	unsigned int len;
 
+	cc_unmap_cipher_request(dev, req_ctx, ivsize, src, dst);
+
 	switch (ctx_p->cipher_mode) {
 	case DRV_CIPHER_CBC:
 		/*
@@ -664,7 +666,6 @@ static void cc_cipher_complete(struct device *dev, void *cc_req, int err)
 		break;
 	}
 
-	cc_unmap_cipher_request(dev, req_ctx, ivsize, src, dst);
 	kzfree(req_ctx->iv);
 
 	skcipher_request_complete(req, err);