The Linux kernel contains a missing NULL pointer check in afs_break_some_callbacks(). If afs_lookup_volume_rcu() returns NULL—such as when the specified volume is unknown—the code will dereference the pointer, potentially causing a kernel crash. A local attacker who can trigger this code path could crash the system as a consequence of a kernel fault. The attack vector is inferred to be local, reachable via normal AFS operations.

The issue exists in the Linux kernel across all released versions that include the afs_break_some_callbacks() function. Specific affected kernel versions are not listed, meaning any kernel prior to the patch that retains the original implementation is vulnerable.

The EPSS score of <1% indicates a very low probability of exploitation in the wild, but the CVSS score of 7.5 implies a high‑severity vulnerability. The null pointer dereference in kernel code continues to imply a high‑risk local exploitation vector that can lead to denial of service. The attack would require a local attacker to supply a volume name that triggers a NULL pointer return during a callback break operation. Given that kernel code is capable of being triggered by normal AFS operations, the risk remains significant for systems that enable AFS support.