---
id: CVE-2026-63889
title: 'scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32'
summary: |-
  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 i…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    07776b7779c9426982c1ad74aad91bd531593790
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    29f126f09e34a425b376b3646c89aa7cc18b142c
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    163bd704d7515c3df6c2e03bcba93d1db79edbff
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    ee57b89e5da9fffbe0d26647e4ff0750dacb9943
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    35461d23744175a78b6280293892cca357c22793
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770
  - >-
    Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 <
    a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153
  - Linux 5.11
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-16T15:33:03.386900Z'
published: '2026-07-19'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:42:10.487Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63889'
references:
  - url: 'https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790'
  - url: 'https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c'
  - url: 'https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff'
  - url: 'https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943'
  - url: 'https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793'
  - url: 'https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770'
  - url: 'https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153'
tags:
  - cve.org
epss: 0.00358
epssPercentile: 0.28003
ingestedAt: '2026-10-16T17:24:46.773Z'
---

## Overview

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.

## Affected

- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 07776b7779c9426982c1ad74aad91bd531593790`
- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 29f126f09e34a425b376b3646c89aa7cc18b142c`
- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 163bd704d7515c3df6c2e03bcba93d1db79edbff`
- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < ee57b89e5da9fffbe0d26647e4ff0750dacb9943`
- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 35461d23744175a78b6280293892cca357c22793`
- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770`
- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153`
- `Linux 5.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.