CVE-2025-40053

In the Linux kernel, the following vulnerability has been resolved:

net: dlink: handle copy_thresh allocation failure

The driver did not handle failure of `netdev_alloc_skb_ip_align()`.
If the allocation failed, dereferencing `skb->protocol` could lead to
a NULL pointer dereference.

This patch tries to allocate `skb`. If the allocation fails, it falls
back to the normal path.

Tested-on: D-Link DGE-550T Rev-A3