crypto: rockchip - update IV buffer to contain the next IV

The Kernel Crypto API request output the next IV data to
IV buffer for CBC implementation. So the last block data of
ciphertext should be copid into assigned IV buffer.

Reported-by: Eric Biggers <ebiggers@google.com>
Fixes: 433cd2c6 ("crypto: rockchip - add crypto driver for rk3288")
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Zhang Zhijie <zhangzj@rock-chips.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/rockchip/rk3288_crypto_ablkcipher.c

@@ -262,9 +262,14 @@ static int rk_set_data_start(struct rk_crypto_info *dev)
 	u8 *src_last_blk = page_address(sg_page(dev->sg_src)) +
 		dev->sg_src->offset + dev->sg_src->length - ivsize;
 
-	/* store the iv that need to be updated in chain mode */
-	if (ctx->mode & RK_CRYPTO_DEC)
+	/* Store the iv that need to be updated in chain mode.
+	 * And update the IV buffer to contain the next IV for decryption mode.
+	 */
+	if (ctx->mode & RK_CRYPTO_DEC) {
 		memcpy(ctx->iv, src_last_blk, ivsize);
+		sg_pcopy_to_buffer(dev->first, dev->src_nents, req->info,
+				   ivsize, dev->total - ivsize);
+	}
 
 	err = dev->load_data(dev, dev->sg_src, dev->sg_dst);
 	if (!err)
@@ -300,13 +305,19 @@ static void rk_iv_copyback(struct rk_crypto_info *dev)
 	struct ablkcipher_request *req =
 		ablkcipher_request_cast(dev->async_req);
 	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	struct rk_cipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
 	u32 ivsize = crypto_ablkcipher_ivsize(tfm);
 
-	if (ivsize == DES_BLOCK_SIZE)
-		memcpy_fromio(req->info, dev->reg + RK_CRYPTO_TDES_IV_0,
-			      ivsize);
-	else if (ivsize == AES_BLOCK_SIZE)
-		memcpy_fromio(req->info, dev->reg + RK_CRYPTO_AES_IV_0, ivsize);
+	/* Update the IV buffer to contain the next IV for encryption mode. */
+	if (!(ctx->mode & RK_CRYPTO_DEC)) {
+		if (dev->aligned) {
+			memcpy(req->info, sg_virt(dev->sg_dst) +
+				dev->sg_dst->length - ivsize, ivsize);
+		} else {
+			memcpy(req->info, dev->addr_vir +
+				dev->count - ivsize, ivsize);
+		}
+	}
 }
 
 static void rk_update_iv(struct rk_crypto_info *dev)