From: Subash Abhinov Kasiviswanathan <subas...@codeaurora.org>
Date: Sun, 3 Dec 2017 23:37:06 -0700
> Add support to send and receive packets over ethernet.
> An example of usage is testing the data path on UML. This can be
> achieved by setting up two UML instances in multicast mode and
> associating rmnet over the UML ethernet device.
>
> Signed-off-by: Subash Abhinov Kasiviswanathan <subas...@codeaurora.org>
> ---
> drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
> b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
> index a46053c..ee20f23 100644
> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
> @@ -15,6 +15,7 @@
>
> #include <linux/netdevice.h>
> #include <linux/netdev_features.h>
> +#include <linux/if_arp.h>
> #include "rmnet_private.h"
> #include "rmnet_config.h"
> #include "rmnet_vnd.h"
> @@ -104,6 +105,12 @@ static void rmnet_set_skb_proto(struct sk_buff *skb)
> {
> struct sk_buff *skbn;
>
> + if (skb->dev->type == ARPHRD_ETHER) {
> + if (skb_headroom(skb) < ETH_HLEN)
> + kfree_skb(skb);
> + skb_push(skb, ETH_HLEN);
> + }
This will crash, you didn't test the new code path that does the
kfree_skb().
You should use an SKB helper function which will realloc the headroom
if ETH_HLEN is not available, instead of failing.
