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authorWillem de Bruijn <willemb@google.com>2014-11-19 13:10:16 -0500
committerDavid S. Miller <davem@davemloft.net>2014-11-21 14:43:07 -0500
commit9c7077622dd917457ced680a23b7f175769471d9 (patch)
tree8c162e5ef188298d9fce81c7d2a6fb216f2d0a5c
parentdf6ce47091620d76bbe036d0af3dc1abad4576c1 (diff)
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>
-rw-r--r--net/packet/af_packet.c29
1 files changed, 21 insertions, 8 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 4cd13d8de44b..58af58026dd2 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2095,6 +2095,18 @@ static void tpacket_destruct_skb(struct sk_buff *skb)
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 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
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 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
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);

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