PT-2026-61206 · Linux · Linux

CVE-2026-63889 · Published 2026-07-19 · Updated 2026-07-19

NVD

CVSS v3.1

8.1

High

Base vector

AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

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 iterating.

Fix

Related Identifiers

CVE-2026-63889

Affected Products

Linux

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-63889 · Security Note
• https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790 · Note
• https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c · Note
• https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff · Note
• https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153 · Note
• https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793 · Note
• https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770 · Note
• https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943 · Note