Revert "net/ieee802154: reject zero-sized raw_sendmsg()"

stable inclusion
from stable-v5.10.150
commit a96336a5f28b91eba4c5575e0434cbf02d8597fd
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a96336a5f28b91eba4c5575e0434cbf02d8597fd

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

[ Upstream commit 2eb2756f ]

This reverts commit 3a4d061c.

There is a v2 which does return zero if zero length is given.
Signed-off-by: NAlexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20221005014750.3685555-1-aahringo@redhat.comSigned-off-by: NStefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

net/ieee802154/socket.c

@@ -252,9 +252,6 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 		return -EOPNOTSUPP;
 	}
 
-	if (!size)
-		return -EINVAL;
-
 	lock_sock(sk);
 	if (!sk->sk_bound_dev_if)
 		dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);