Critical · published February 28, 2024
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.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 4.9, < 4.9.269 | 4.9.269 |
| linux/linux_kernel | ≥ 4.10, < 4.14.233 | 4.14.233 |
| linux/linux_kernel | ≥ 4.15, < 4.19.191 | 4.19.191 |
| linux/linux_kernel | ≥ 4.20, < 5.4.119 | 5.4.119 |
| linux/linux_kernel | ≥ 5.5, < 5.10.37 | 5.10.37 |
| linux/linux_kernel | ≥ 5.11, < 5.11.21 | 5.11.21 |
| linux/linux_kernel | ≥ 5.12, < 5.12.4 | 5.12.4 |