---
id: CVE-2026-74331
title: 'firmware_loader: Fix recursive lock in device_cache_fw_images()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  firmware_loader: Fix recursive lock in device_cache_fw_images()

  A recursive locking deadlock can occur in the firmware loader's power
  management notification handler.
  …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    806cb8fabfde7f830da5ae87777d52fdf50c4774
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    7865a1bfd20d10c03b083a5fc392d907ca5099b3
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    490b0385e4cfac691f7b18dde821c13e77b4770b
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    38149b57427c736c08d9aa4c7b87deacd53e9e63
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    a5b2a68a391b05d54552f13548a72a46c65006f7
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    f25d6e4ec4c257030592bd671f113cf9584c52f0
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    c0f2dedd41fe14dbe076c1672214802fb42cd8c8
  - >-
    Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 <
    d3ec78f8f8d48a04a9fac38d47275c34645e5103
  - Linux 3.7
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:56:13.937095Z'
published: '2026-08-15'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:05:44.205Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74331'
references:
  - url: 'https://git.kernel.org/stable/c/806cb8fabfde7f830da5ae87777d52fdf50c4774'
  - url: 'https://git.kernel.org/stable/c/7865a1bfd20d10c03b083a5fc392d907ca5099b3'
  - url: 'https://git.kernel.org/stable/c/490b0385e4cfac691f7b18dde821c13e77b4770b'
  - url: 'https://git.kernel.org/stable/c/38149b57427c736c08d9aa4c7b87deacd53e9e63'
  - url: 'https://git.kernel.org/stable/c/a5b2a68a391b05d54552f13548a72a46c65006f7'
  - url: 'https://git.kernel.org/stable/c/f25d6e4ec4c257030592bd671f113cf9584c52f0'
  - url: 'https://git.kernel.org/stable/c/c0f2dedd41fe14dbe076c1672214802fb42cd8c8'
  - url: 'https://git.kernel.org/stable/c/d3ec78f8f8d48a04a9fac38d47275c34645e5103'
tags:
  - cve.org
epss: 0.00236
epssPercentile: 0.14728
ingestedAt: '2026-11-06T18:00:12.565Z'
---

## Overview

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

firmware_loader: Fix recursive lock in device_cache_fw_images()

A recursive locking deadlock can occur in the firmware loader's power
management notification handler.

During system suspend or hibernation preparation, fw_pm_notify() calls
device_cache_fw_images(). This function acquires fw_lock to set the
firmware cache state to FW_LOADER_START_CACHE and then iterates over all
devices using dpm_for_each_dev() while still holding the lock.

For each device, dev_cache_fw_image() schedules asynchronous work to cache
the firmware. If memory allocation for the async work entry fails (e.g., in
out-of-memory conditions), async_schedule_node_domain() falls back to
executing the work function synchronously in the current thread.

The synchronous execution path (__async_dev_cache_fw_image() ->
cache_firmware() -> request_firmware() -> assign_fw()) attempts to acquire
fw_lock again. Since the current thread already holds fw_lock, this results
in a recursive locking deadlock.

Fix this by releasing fw_lock immediately after updating the cache state
and before calling dpm_for_each_dev(). The lock is only needed to protect
the state update. Concurrent firmware requests will correctly see the
FW_LOADER_START_CACHE state and use the piggyback mechanism, which is
independently protected by its own fwc->name_lock.

## Affected

- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < 806cb8fabfde7f830da5ae87777d52fdf50c4774`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < 7865a1bfd20d10c03b083a5fc392d907ca5099b3`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < 490b0385e4cfac691f7b18dde821c13e77b4770b`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < 38149b57427c736c08d9aa4c7b87deacd53e9e63`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < a5b2a68a391b05d54552f13548a72a46c65006f7`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < f25d6e4ec4c257030592bd671f113cf9584c52f0`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < c0f2dedd41fe14dbe076c1672214802fb42cd8c8`
- `Linux >= ac39b3ea73aacde876d1d5ee1ca3e2719f771482 < d3ec78f8f8d48a04a9fac38d47275c34645e5103`
- `Linux 3.7`

## Remediation

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