[PATCH] can: add missing initialisations in CAN related skbuffs

[PATCH] can: add missing initialisations in CAN related skbuffs

[Oliver Hartkopp]

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@peloton-tech.com>
Reported-by: Daniel Steer <daniel.steer@mclaren.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
 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 3c82e02..b0f6924 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -579,6 +579,10 @@ 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;
 
@@ -603,6 +607,10 @@ 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 66e0804..32d710e 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -259,6 +259,9 @@ 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);
 
-- 
2.1.4

Re: [PATCH] can: add missing initialisations in CAN related skbuffs

[Marc Kleine-Budde]

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On 02/23/2015 08:37 PM, Oliver Hartkopp wrote:
> 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@peloton-tech.com>
> Reported-by: Daniel Steer <daniel.steer@mclaren.com>
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>

Thanks, applied to can/master, added stable on Cc.

Marc

-- 
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