[PATCH 4.9 144/206] s390/crypto: unlock on error in prng_tdes_read()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 9e6e7c74315095fd40f41003850690c711e44420 upstream.

We added some new locking but forgot to unlock on error.

Fixes: 57127645d79d ("s390/zcrypt: Introduce new SHA-512 based Pseudo Random Generator.")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/s390/crypto/prng.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/s390/crypto/prng.c
+++ b/arch/s390/crypto/prng.c
@@ -507,8 +507,10 @@ static ssize_t prng_tdes_read(struct fil
 		prng_data->prngws.byte_counter += n;
 		prng_data->prngws.reseed_counter += n;
 
-		if (copy_to_user(ubuf, prng_data->buf, chunk))
-			return -EFAULT;
+		if (copy_to_user(ubuf, prng_data->buf, chunk)) {
+			ret = -EFAULT;
+			break;
+		}
 
 		nbytes -= chunk;
 		ret += chunk;