can: dev: prevent potential information leak in can_fill_info()

[ Upstream commit b552766 ]

The "bec" struct isn't necessarily always initialized. For example, the
mcp251xfd_get_berr_counter() function doesn't initialize anything if the
interface is down.

Fixes: 52c793f ("can: netlink support for bus-error reporting and counters")
Link: https://lore.kernel.org/r/YAkaRdRJncsJO8Ve@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/can/dev.c

@@ -987,7 +987,7 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct can_priv *priv = netdev_priv(dev);
 	struct can_ctrlmode cm = {.flags = priv->ctrlmode};
-	struct can_berr_counter bec;
+	struct can_berr_counter bec = { };
 	enum can_state state = priv->state;
 
 	if (priv->do_get_state)