CVE-2026-63889

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32

An adjacent Fibre Channel fabric actor that can deliver an FPIN ELS

frame to an lpfc or qla2xxx Linux initiator can trigger a non-return in

the generic FC transport. This is not a local userspace or IP network

path; the attacker must be able to inject fabric traffic, for example as

a compromised switch or fabric controller, or as a same-zone N_Port on a

fabric that permits source spoofing.

The Link-Integrity and Peer-Congestion FPIN walkers used a u8 loop

counter against the 32-bit on-wire pname_count field, and did not bound

pname_count by the descriptor body already validated by the TLV walker.

A pname_count of 256 therefore wraps the counter and keeps the loop

condition true indefinitely.

Factor the shared pname_list[] walk into one helper, widen the counter

to u32, and clamp pname_count against the entries that fit in the

descriptor body before ite

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References