[PATCH] crypto: atmel-sha204a - Fix OOM ->tfm_count leak

[Thorsten Blum]

If memory allocation fails, decrement ->tfm_count to avoid blocking
future reads.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: da001fb651b0 ("crypto: atmel-i2c - add support for SHA204A random number generator")
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx>
---
 drivers/crypto/atmel-sha204a.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 2081a4d538d0..63633d2b8763 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -53,9 +53,10 @@ static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *data,
 		rng->priv = 0;
 	} else {
 		work_data = kmalloc(sizeof(*work_data), GFP_ATOMIC);
-		if (!work_data)
+		if (!work_data) {
+			atomic_dec(&i2c_priv->tfm_count);
 			return -ENOMEM;
-
+		}
 		work_data->ctx = i2c_priv;
 		work_data->client = i2c_priv->client;
 
-- 
Thorsten Blum <thorsten.blum@xxxxxxxxx>
GPG: 1D60 735E 8AEF 3BE4 73B6  9D84 7336 78FD 8DFE EAD4