can: add missing initialisations in CAN related skbuffs

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>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 3c82e02e3dae..b0f69248cb71 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;