crypto: chtls - fix null dereference chtls_free_uld()

call chtls_free_uld() only for the initialized cdev,
this fixes NULL dereference in chtls_free_uld()

Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: Atul Gupta <atul.gupta@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/chelsio/chtls/chtls.h

@@ -96,6 +96,10 @@ enum csk_flags {
 	CSK_CONN_INLINE,	/* Connection on HW */
 };
 
+enum chtls_cdev_state {
+	CHTLS_CDEV_STATE_UP = 1
+};
+
 struct listen_ctx {
 	struct sock *lsk;
 	struct chtls_dev *cdev;
@@ -146,6 +150,7 @@ struct chtls_dev {
 	unsigned int send_page_order;
 	int max_host_sndbuf;
 	struct key_map kmap;
+	unsigned int cdev_state;
 };
 
 struct chtls_hws {

drivers/crypto/chelsio/chtls/chtls_main.c

@@ -160,6 +160,7 @@ static void chtls_register_dev(struct chtls_dev *cdev)
 	tlsdev->hash = chtls_create_hash;
 	tlsdev->unhash = chtls_destroy_hash;
 	tls_register_device(&cdev->tlsdev);
+	cdev->cdev_state = CHTLS_CDEV_STATE_UP;
 }
 
 static void chtls_unregister_dev(struct chtls_dev *cdev)
@@ -281,8 +282,10 @@ static void chtls_free_all_uld(void)
 	struct chtls_dev *cdev, *tmp;
 
 	mutex_lock(&cdev_mutex);
-	list_for_each_entry_safe(cdev, tmp, &cdev_list, list)
-		chtls_free_uld(cdev);
+	list_for_each_entry_safe(cdev, tmp, &cdev_list, list) {
+		if (cdev->cdev_state == CHTLS_CDEV_STATE_UP)
+			chtls_free_uld(cdev);
+	}
 	mutex_unlock(&cdev_mutex);
 }