CVE-2022-4129

A flaw was found in the Linux kernels Layer 2 Tunneling Protocol (L2TP). A missing lock when clearing sk_user_data can lead to a race condition and NULL pointer dereference. A local user could use this flaw to potentially crash the system causing a denial of service.

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7X5SPXMXXFANDASPCKER2JIQO2F3UHCP/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AM5KFIE6JNZXHBA5A2KYDZAT3MEX2B67/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JOKXNIM2R4FQCDRQV67UMAY6EBC72QFG/
• https://lore.kernel.org/all/20221114191619.124659-1-jakub%40cloudflare.com/t
• https://lore.kernel.org/netdev/20221121085426.21315-1-jakub%40cloudflare.com/t