[PATCH 5.15.y] crypto: atmel-sha204a - Fix OOM ->tfm_count leak

[Sasha Levin <sashal@kernel.org>]

From: Thorsten Blum <thorsten.blum@linux.dev>

[ Upstream commit d240b079a37e90af03fd7dfec94930eb6c83936e ]

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

Cc: stable@vger.kernel.org
Fixes: da001fb651b0 ("crypto: atmel-i2c - add support for SHA204A random number generator")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[ adapted kmalloc_obj() macro to kmalloc(sizeof()) ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 0ef92109ce22a..64d5ba13f4baf 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -52,9 +52,10 @@ 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;
 
-- 
2.51.0