---
id: CVE-2026-74407
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  wifi: ath11k: cancel SSR work items during PCI shutdown

  A reboot can crash the kernel if it overlaps with WLAN firmware crash
  recovery (SSR)
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  wifi: ath11k: cancel SSR work items during PCI shutdown

  A reboot can crash the kernel if it overlaps with WLAN firmware crash
  recovery (SSR). The crash is a NULL point…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 13da397f884d9c9a3fb6616206eeb6c6ab097287 <
    6dd3701facc0cee62d6682e49eed64499f9d0e43
  - >-
    Linux >= 13da397f884d9c9a3fb6616206eeb6c6ab097287 <
    53dd29e8aeb2a1b5f079178551836b85fc6b53df
  - >-
    Linux >= 13da397f884d9c9a3fb6616206eeb6c6ab097287 <
    8c79aac429b583301f387374ff37c59be671df87
  - Linux 5.19
published: '2026-08-15'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:19.040'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74407'
references:
  - url: 'https://git.kernel.org/stable/c/53dd29e8aeb2a1b5f079178551836b85fc6b53df'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6dd3701facc0cee62d6682e49eed64499f9d0e43'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8c79aac429b583301f387374ff37c59be671df87'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00375
epssPercentile: 0.28655
ingestedAt: '2026-09-21T13:37:22.838Z'
---

## Overview

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

wifi: ath11k: cancel SSR work items during PCI shutdown

A reboot can crash the kernel if it overlaps with WLAN firmware crash
recovery (SSR). The crash is a NULL pointer dereference in the MHI teardown
path while freeing DMA-backed MHI contexts.

Simplified trace:
  dma_free_attrs
  mhi_deinit_dev_ctxt [mhi]
  ath11k_pci_power_down [ath11k_pci]
  ath11k_pci_shutdown [ath11k_pci]
  device_shutdown
  kernel_restart

On the host side, SSR is driven by the MHI RDDM callback, which queues
reset_work to perform device recovery. reset_work power-cycles the device
by calling ath11k_hif_power_down() followed by ath11k_hif_power_up(). The
power-down phase deinitializes MHI and frees DMA resources.

Shutdown/reboot runs fully asynchronously with this RDDM-driven SSR
recovery flow. As a result, the shutdown path
(ath11k_pci_shutdown() -> ath11k_pci_power_down()) can race with the SSR
recovery sequence.

Fix this by canceling SSR-related work items during PCI shutdown, marking
the device as unregistering, and serializing the RDDM callback path that
checks and queues reset_work. This ensures that no new SSR recovery work
can be queued once teardown has started, and that any in-flight recovery
work is fully synchronized before device power-down, preventing MHI
teardown and DMA resource freeing from running more than once.

Note: This issue only affects PCI/MHI-based devices. AHB-based ath11k
devices do not queue reset_work in normal SSR flows.

Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04866.5-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1

## Remediation

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