CVE-2021-47224

In the Linux kernel, the following vulnerability has been resolved: net:
ll_temac: Make sure to free skb when it is completely used With the skb
pointer piggy-backed on the TX BD, we have a simple and efficient way to
free the skb buffer when the frame has been transmitted. But in order to
avoid freeing the skb while there are still fragments from the skb in use,
we need to piggy-back on the TX BD of the skb, not the first. Without this,
we are doing use-after-free on the DMA side, when the first BD of a multi
TX BD packet is seen as completed in xmit_done, and the remaining BDs are
still being processed.