[PATCH 07/22] crypto: s390/paes - 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: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Andrei Botila <andrei.botila@xxxxxxx>
---
 arch/s390/crypto/paes_s390.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/s390/crypto/paes_s390.c b/arch/s390/crypto/paes_s390.c
index f3caeb17c85b..7f0861c6f019 100644
--- a/arch/s390/crypto/paes_s390.c
+++ b/arch/s390/crypto/paes_s390.c
@@ -494,6 +494,9 @@ static int xts_paes_crypt(struct skcipher_request *req, unsigned long modifier)
 		u8 init[16];
 	} xts_param;
 
+	if (!req->cryptlen)
+		return 0;
+
 	ret = skcipher_walk_virt(&walk, req, false);
 	if (ret)
 		return ret;
-- 
2.17.1