CVE-2022-49921 net: sched: Fix use after free in red_enqueue()
A use-after-free flaw in the Linux kernel's network scheduler allows attackers to potentially execute code or cause a system crash.
- 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-2022-49921?
CVE-2022-49921 is a high-severity use after free vulnerability in Linux kernel, published on 1 May 2025. 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: sched: Fix use after free in red_enqueue()
We can't use "skb" again after passing it to qdisc_enqueue(). This is basically identical to commit 2f09707d0c97 ("sch_sfb: Also store skb len before calling child enqueue").
Weakness: CWE-416
Which versions are affected by CVE-2022-49921?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49921?
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-2022-49921 being exploited?
There is no known exploitation of CVE-2022-49921 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49921, GHSA-5gp6-334q-267g, UBUNTU-CVE-2022-49921.