From dc633700f00f726e027846a318c5ffeb8deaaeda Mon Sep 17 00:00:00 2001 From: Zhengchao Shao Date: Wed, 27 Jul 2022 17:33:12 +0800 Subject: [PATCH] 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: syzbot+5ea725c25d06fb9114c4@syzkaller.appspotmail.com Fixes: fd1894224407 ("bpf: Don't redirect packets with invalid pkt_len") Signed-off-by: Zhengchao Shao Signed-off-by: David S. Miller --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index d08c4728523b..5cbe07116e04 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -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; }