packet: make packet_snd fail on len smaller than l2 header
When sending packets out with PF_PACKET, SOCK_RAW, ensure that the
packet is at least as long as the device's expected link layer header.
This check already exists in tpacket_snd, but not in packet_snd.
Also rate limit the warning in tpacket_snd.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 4cd13d8..58af5802 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2095,6 +2095,18 @@
sock_wfree(skb);
}
+static bool ll_header_truncated(const struct net_device *dev, int len)
+{
+ /* net device doesn't like empty head */
+ if (unlikely(len <= dev->hard_header_len)) {
+ net_warn_ratelimited("%s: packet size is too short (%d < %d)\n",
+ current->comm, len, dev->hard_header_len);
+ return true;
+ }
+
+ return false;
+}
+
static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
void *frame, struct net_device *dev, int size_max,
__be16 proto, unsigned char *addr, int hlen)
@@ -2170,12 +2182,8 @@
if (unlikely(err < 0))
return -EINVAL;
} else if (dev->hard_header_len) {
- /* net device doesn't like empty head */
- if (unlikely(tp_len <= dev->hard_header_len)) {
- pr_err("packet size is too short (%d < %d)\n",
- tp_len, dev->hard_header_len);
+ if (ll_header_truncated(dev, tp_len))
return -EINVAL;
- }
skb_push(skb, dev->hard_header_len);
err = skb_store_bits(skb, 0, data,
@@ -2500,9 +2508,14 @@
skb_set_network_header(skb, reserve);
err = -EINVAL;
- if (sock->type == SOCK_DGRAM &&
- (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
- goto out_free;
+ if (sock->type == SOCK_DGRAM) {
+ offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
+ if (unlikely(offset) < 0)
+ goto out_free;
+ } else {
+ if (ll_header_truncated(dev, len))
+ goto out_free;
+ }
/* Returns -EFAULT on error */
err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);