[3.11.y.z extended stable] Patch "sfc: Add length checks to efx_xmit_with_hwtstamp() and" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    sfc: Add length checks to efx_xmit_with_hwtstamp() and

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From dd0e8606527dee02d8996bd0a8a129bbbdee4e49 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <bhutchings at solarflare.com>
Date: Fri, 6 Dec 2013 19:26:40 +0000
Subject: sfc: Add length checks to efx_xmit_with_hwtstamp() and
 efx_ptp_is_ptp_tx()

commit e5a498e943fbc497f236ab8cf31366c75f337ce6 upstream.

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: 7c236c43b838 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings at solarflare.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/sfc/ptp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index b495394..6ddec68 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -982,7 +982,11 @@ 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);
 }

--
1.8.3.2