CVE-2022-49649 xen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue

In the Linux kernel, the following vulnerability has been resolved: xen/netback: avoid entering xenvifrxnextskb with an empty rx queue xenvifrxnextskb is expecting the rx queue not being empty, but in case the loop in xenvifrxaction is doing multiple iterations, the availability of another skb in...