Commit dc633700 authored by Zhengchao Shao's avatar Zhengchao Shao Committed by David S. Miller
Browse files

net/af_packet: check len when min_header_len equals to 0 



User can use AF_PACKET socket to send packets with the length of 0.
When min_header_len equals to 0, packet_snd will call __dev_queue_xmit
to send packets, and sock->type can be any type.

Reported-by: default avatar <syzbot+5ea725c25d06fb9114c4@syzkaller.appspotmail.com>
Fixes: fd189422 ("bpf: Don't redirect packets with invalid pkt_len")
Signed-off-by: default avatarZhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3b1c3147

net/packet/af_packet.c

+2 −2
Original line number Diff line number Diff line
@@ -3037,8 +3037,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	if (err)

		goto out_free;



	if (sock->type == SOCK_RAW &&

	    !dev_validate_header(dev, skb->data, len)) {

	if ((sock->type == SOCK_RAW &&

	     !dev_validate_header(dev, skb->data, len)) || !skb->len) {

		err = -EINVAL;

		goto out_free;

	}