can: isotp: return -EADDRNOTAVAIL when reading from unbound socket

stable inclusion
from stable-v5.10.110
commit f402c498651993de361f349ac0cedb9f8622319f
bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f402c498651993de361f349ac0cedb9f8622319f

--------------------------------

[ Upstream commit 30ffd53 ]

When reading from an unbound can-isotp socket the syscall blocked
indefinitely. As unbound sockets (without given CAN address information)
do not make sense anyway we directly return -EADDRNOTAVAIL on read()
analogue to the known behavior from sendmsg().

Fixes: e057dd3 ("can: add ISO 15765-2:2016 transport protocol")
Link: linux-can/can-utils#349
Link: https://lore.kernel.org/all/[email protected]
Suggested-by: Derek Will <[email protected]>
Signed-off-by: Oliver Hartkopp <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Yu Liao <[email protected]>
Reviewed-by: Wei Li <[email protected]>
Signed-off-by: Zheng Zengkai <[email protected]>

net/can/isotp.c

@@ -1003,12 +1003,16 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 {
 	struct sock *sk = sock->sk;
 	struct sk_buff *skb;
+	struct isotp_sock *so = isotp_sk(sk);
 	int err = 0;
 	int noblock;
 
 	noblock = flags & MSG_DONTWAIT;
 	flags &= ~MSG_DONTWAIT;
 
+	if (!so->bound)
+		return -EADDRNOTAVAIL;
+
 	skb = skb_recv_datagram(sk, flags, noblock, &err);
 	if (!skb)
 		return err;