Linux · Linux Kernel · CVE-2021-47013
**Name of the Vulnerable Software and Affected Versions**
Linux kernel (affected versions not specified)
**Description**
A use after free issue has been resolved in the Linux kernel. The issue occurs in the `emac mac tx buf send` function, which calls `emac tx fill tpd(..,skb,..)`. If an error happens in `emac tx fill tpd()`, the `skb` will be freed via `dev kfree skb(skb)` in the error branch of `emac tx fill tpd()`. However, the freed `skb` is still used via `skb->len` by `netdev sent queue(,skb->len)`. To fix this issue, the patch assigns `skb->len` to `'len'` before the possible free and uses `'len'` instead of `skb->len` later.
**Recommendations**
At the moment, there is no information about a newer version that contains a fix for this vulnerability.