---
id: CVE-2026-89856
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  scsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation

  ha->msix_count is u16, but ha->max_req_queues, ha->max_rsp_queues and
  ha->max_qpairs are u8
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  scsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation

  ha->msix_count is u16, but ha->max_req_queues, ha->max_rsp_queues and
  ha->max_qpairs are u8. Derivi…
severity: high
cvss: 8.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    cf623d32761b00f221a9cfded3303d56e84b429d
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    9eeddbeaa896f39d943644b16d83a6ad0ceab255
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    802068b9b683b8008fcccbf6e9ad133e597ec87c
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    e80adfeac61b4d5db7ffe0f5af43999c33a4145e
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    2efe50b2da829909023de4a2eb87badb7cfa53cc
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    7a448f5ed0b283dbde4e9183dd1e98c221432dab
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    33c77254e6e91f37c72c7fad4051777452b10de8
  - >-
    Linux >= d74595278f4ab192af66d9e60a9087464638beee <
    ebfd35c64433821bd5619a6d07ccc2df8b5b1de3
  - Linux 4.10
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:18:13.507'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89856'
references:
  - url: 'https://git.kernel.org/stable/c/2efe50b2da829909023de4a2eb87badb7cfa53cc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/33c77254e6e91f37c72c7fad4051777452b10de8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7a448f5ed0b283dbde4e9183dd1e98c221432dab'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/802068b9b683b8008fcccbf6e9ad133e597ec87c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9eeddbeaa896f39d943644b16d83a6ad0ceab255'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cf623d32761b00f221a9cfded3303d56e84b429d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e80adfeac61b4d5db7ffe0f5af43999c33a4145e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ebfd35c64433821bd5619a6d07ccc2df8b5b1de3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-16T10:53:53.992Z'
epss: 0.00196
epssPercentile: 0.08192
---

## Overview

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

scsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation

ha->msix_count is u16, but ha->max_req_queues, ha->max_rsp_queues and
ha->max_qpairs are u8. Deriving the queue count as
"ha->max_req_queues = ha->msix_count - 1" therefore truncates: a board
(or a misconfigured/malicious hot-plugged device) advertising 257 MSI-X
vectors yields msix_count - 1 == 256, which truncates to 0. An MSI-X
count of 1 zeroes it as well, and in target mode the subsequent
"ha->max_req_queues--" then underflows 0 to 255.

When the count is 0, qla2x00_alloc_queues() calls
kzalloc_objs(struct req_que *, 0), which returns ZERO_SIZE_PTR. That is
not NULL, so the allocation check passes and the following
"ha->req_q_map[0] = req" dereferences ZERO_SIZE_PTR, corrupting memory
or crashing the kernel.

Add qla_calc_queue_count() to clamp the derived value into
[1, QLA_MAX_QUEUES - 1] so it always fits in u8 and is never zero, and
use it at all three derivation sites (qla25xx_iospace_config(),
qla83xx_iospace_config() and qla24xx_enable_msix()). Also guard the
target-mode decrement so it cannot reintroduce a zero (which would in
turn underflow max_qpairs).

## Remediation

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