[PATCH 22/22] crypto: vmx - add check for xts input length equal to zero

[Andrei Botila]

From: Andrei Botila <andrei.botila@xxxxxxx>

Standardize the way input lengths equal to 0 are handled in all skcipher
algorithms. All the algorithms return 0 for input lengths equal to zero.

Cc: "Breno Leitão" <leitao@xxxxxxxxxx>
Cc: Nayna Jain <nayna@xxxxxxxxxxxxx>
Cc: Paulo Flabiano Smorigo <pfsmorigo@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Andrei Botila <andrei.botila@xxxxxxx>
---
 drivers/crypto/vmx/aes_xts.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
index 9fee1b1532a4..33107c9e2656 100644
--- a/drivers/crypto/vmx/aes_xts.c
+++ b/drivers/crypto/vmx/aes_xts.c
@@ -84,6 +84,9 @@ static int p8_aes_xts_crypt(struct skcipher_request *req, int enc)
 	u8 tweak[AES_BLOCK_SIZE];
 	int ret;
 
+	if (!req->cryptlen)
+		return 0;
+
 	if (req->cryptlen < AES_BLOCK_SIZE)
 		return -EINVAL;
 
-- 
2.17.1