| From foo@baz Wed Aug 22 09:42:09 CEST 2018 |
| From: Willem de Bruijn <willemb@google.com> |
| Date: Wed, 11 Jul 2018 12:00:45 -0400 |
| Subject: packet: reset network header if packet shorter than ll reserved space |
| |
| From: Willem de Bruijn <willemb@google.com> |
| |
| [ Upstream commit 993675a3100b16a4c80dfd70cbcde8ea7127b31d ] |
| |
| If variable length link layer headers result in a packet shorter |
| than dev->hard_header_len, reset the network header offset. Else |
| skb->mac_len may exceed skb->len after skb_mac_reset_len. |
| |
| packet_sendmsg_spkt already has similar logic. |
| |
| Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation") |
| Signed-off-by: Willem de Bruijn <willemb@google.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/packet/af_packet.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/net/packet/af_packet.c |
| +++ b/net/packet/af_packet.c |
| @@ -2917,6 +2917,8 @@ static int packet_snd(struct socket *soc |
| goto out_free; |
| } else if (reserve) { |
| skb_reserve(skb, -reserve); |
| + if (len < reserve) |
| + skb_reset_network_header(skb); |
| } |
| |
| /* Returns -EFAULT on error */ |
