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@peloton-tech.com>
Reported-by: Daniel Steer <daniel.steer@mclaren.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index a4694aa20a3e02aaa38605613f9cb576fedf2a90..f66aeb79abdf266604bfb39c94de40a5ad32f47a 100644 (file)
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -503,6 +503,14 @@ 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);
+
+       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 f59859a3f5620d5a8d4e344b68de605817a72a61..d3668c55b088bc940e1848c4b551cdb6e2626448 100644 (file)
--- 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);