From: Zhengchao Shao shaozhengchao@huawei.com
commit dc633700f00f726e027846a318c5ffeb8deaaeda upstream.
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 shaozhengchao@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3037,8 +3037,8 @@ static int packet_snd(struct socket *soc 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; }