CVE-2022-49669 mptcp: fix race on unaccepted mptcp sockets
A race condition in the Linux kernel MPTCP subsystem allows use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- 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-2022-49669?
CVE-2022-49669 is a high-severity use after free vulnerability in Linux kernel, published on 26 Feb 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:
mptcp: fix race on unaccepted mptcp sockets
When the listener socket owning the relevant request is closed, it frees the unaccepted subflows and that causes later deletion of the paired MPTCP sockets.
The mptcp socket's worker can run in the time interval between such delete operations. When that happens, any access to msk->first will cause an UaF access, as the subflow cleanup did not cleared such field in the mptcp socket.
Address the issue explicitly traversing the listener socket accept queue at close time and performing the needed cleanup on the pending msk.
Note that the locking is a bit tricky, as we need to acquire the msk socket lock, while still owning the subflow socket one.
Weakness: CWE-416
Which versions are affected by CVE-2022-49669?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49669?
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-2022-49669 being exploited?
There is no known exploitation of CVE-2022-49669 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49669, GHSA-97f5-6j52-rp35, UBUNTU-CVE-2022-49669.