[PATCH] crypto: ti-dthev2 - Fix potential invalid access when device list is empty

[Hongling Zeng]

list_first_entry() never returns NULL - if the list is empty, it still
returns a pointer to an invalid object, leading to potential invalid
memory access when dereferenced.

Fix this by using list_first_entry_or_null instead of list_first_entry.

Fixes: 52f641bc63a4 ("crypto: ti - Add driver for DTHE V2 AES Engine (ECB, CBC)")
Signed-off-by: Hongling Zeng <zenghongling@xxxxxxxxxx>
---
 drivers/crypto/ti/dthev2-common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/ti/dthev2-common.c b/drivers/crypto/ti/dthev2-common.c
index a2ad79bec105..cc0244938267 100644
--- a/drivers/crypto/ti/dthev2-common.c
+++ b/drivers/crypto/ti/dthev2-common.c
@@ -40,7 +40,7 @@ struct dthe_data *dthe_get_dev(struct dthe_tfm_ctx *ctx)
 		return ctx->dev_data;
 
 	spin_lock_bh(&dthe_dev_list.lock);
-	dev_data = list_first_entry(&dthe_dev_list.dev_list, struct dthe_data, list);
+	dev_data = list_first_entry_or_null(&dthe_dev_list.dev_list, struct dthe_data, list);
 	if (dev_data)
 		list_move_tail(&dev_data->list, &dthe_dev_list.dev_list);
 	spin_unlock_bh(&dthe_dev_list.lock);
-- 
2.25.1