CVE-2021-47224 net: ll_temac: Make sure to free skb when it is completely used
A use-after-free vulnerability in the Linux kernel's ll_temac network driver allows attackers to cause denial of service or potentially execute code via crafted network packets.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47224?
CVE-2021-47224 is a high-severity use after free vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-416
Which versions are affected by CVE-2021-47224?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47224?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2021-47224 being exploited?
There is no known exploitation of CVE-2021-47224 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47224, GHSA-cqgv-cq5q-68pf, UBUNTU-CVE-2021-47224.