Oracle Linux: CVE-2021-47013: ELSA-2024-3618: kernel update (MODERATE)

In the Linux kernel, the following vulnerability has been resolved:
net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send
In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..).
If some error happens in emac_tx_fill_tpd(), the skb will be freed via
dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd().
But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len).
As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len,
thus my patch assigns skb->len to 'len' before the possible free and
use 'len' instead of skb->len later.
A use-after-free flaw was found in the Linux kernel’s Qualcomm Gigabit Ethernet Media Access Controller (EMAC) driver in how a user triggers an error path in the emac_tx_fill_tpd function. This flaw allows a local user to crash or potentially escalate their privileges on the system.