[3.16.y-ckt stable] Patch "can: add missing initialisations in CAN related skbuffs" has been added to staging queue

[Luis Henriques]

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

    can: add missing initialisations in CAN related skbuffs

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt9.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 96336fb939094ea3e6624ac1e0e5ce10a035147e Mon Sep 17 00:00:00 2001
From: Oliver Hartkopp <socketcan at hartkopp.net>
Date: Mon, 23 Feb 2015 20:37:54 +0100
Subject: can: add missing initialisations in CAN related skbuffs

commit 969439016d2cf61fef53a973d7e6d2061c3793b1 upstream.

When accessing CAN network interfaces with AF_PACKET sockets e.g. by dhclient
this can lead to a skb_under_panic due to missing skb initialisations.

Add the missing initialisations at the CAN skbuff creation times on driver
level (rx path) and in the network layer (tx path).

Reported-by: Austin Schuh <austin at peloton-tech.com>
Reported-by: Daniel Steer <daniel.steer at mclaren.com>
Signed-off-by: Oliver Hartkopp <socketcan at hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/can/dev.c | 8 ++++++++
 net/can/af_can.c      | 3 +++
 2 files changed, 11 insertions(+)

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 9b04d0a9356d..c543c3aaee4d 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -501,6 +501,10 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 	skb->pkt_type = PACKET_BROADCAST;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;

+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
 	can_skb_reserve(skb);
 	can_skb_prv(skb)->ifindex = dev->ifindex;

@@ -525,6 +529,10 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 	skb->pkt_type = PACKET_BROADCAST;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;

+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
 	can_skb_reserve(skb);
 	can_skb_prv(skb)->ifindex = dev->ifindex;

diff --git a/net/can/af_can.c b/net/can/af_can.c
index ce82337521f6..d6030d6949df 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -262,6 +262,9 @@ int can_send(struct sk_buff *skb, int loop)
 		goto inval_skb;
 	}

+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
 	skb_reset_transport_header(skb);