sfc: Add length checks to efx_xmit_with_hwtstamp() and efx_ptp_is_ptp_tx()

efx_ptp_is_ptp_tx() must be robust against skbs from raw sockets that
have invalid IPv4 and UDP headers.

Add checks that:
- the transport header has been found
- there is enough space between network and transport header offset
  for an IPv4 header
- there is enough space after the transport header offset for a
  UDP header

Fixes: 7c236c43b8 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
This commit is contained in:
Ben Hutchings 2013-12-06 19:26:40 +00:00
parent e1ca87bb1b
commit e5a498e943

View File

@ -989,7 +989,11 @@ bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
skb->len >= PTP_MIN_LENGTH &&
skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM &&
likely(skb->protocol == htons(ETH_P_IP)) &&
skb_transport_header_was_set(skb) &&
skb_network_header_len(skb) >= sizeof(struct iphdr) &&
ip_hdr(skb)->protocol == IPPROTO_UDP &&
skb_headlen(skb) >=
skb_transport_offset(skb) + sizeof(struct udphdr) &&
udp_hdr(skb)->dest == htons(PTP_EVENT_PORT);
}