From 03ac583eefc9bc980213c53a79abc32a5539756e Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun, 2 Oct 2022 01:43:44 +0900
Subject: [PATCH] net/ieee802154: reject zero-sized raw_sendmsg()

[ Upstream commit 3a4d061c699bd3eedc80dc97a4b2a2e1af83c6f5 ]

syzbot is hitting skb_assert_len() warning at raw_sendmsg() for ieee802154
socket. What commit dc633700f00f726e ("net/af_packet: check len when
min_header_len equals to 0") does also applies to ieee802154 socket.

Link: https://syzkaller.appspot.com/bug?extid=5ea725c25d06fb9114c4
Reported-by: syzbot <syzbot+5ea725c25d06fb9114c4@syzkaller.appspotmail.com>
Fixes: fd1894224407c484 ("bpf: Don't redirect packets with invalid pkt_len")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ieee802154/socket.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
index a92b11999e5f..72637d5994d8 100644
--- a/net/ieee802154/socket.c
+++ b/net/ieee802154/socket.c
@@ -252,6 +252,9 @@ 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);