---
id: CVE-2026-64251
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

  pwrseq_debugfs_seq_next() declares 'next' with __free(put_device),
  which causes put_device() to be called…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

  pwrseq_debugfs_seq_next() declares 'next' with __free(put_device),
  which causes put_device() to be called…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
published: '2026-07-24'
updated: '2026-07-27'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64251'
references:
  - url: 'https://git.kernel.org/stable/c/257595adf9dac15ae1edd9d07753fbc576a7583d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/73569a44fca2992f0ca4a4c0104069741b9873a0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ba0b9f04c7a5f9887b8ce672eaf049502c0548ec'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e91df6d273445c03f5aa302bfe147eda33d45794'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00117
epssPercentile: 0.01485
ingestedAt: '2026-07-27T06:16:49.504Z'
---

## Overview

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

pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

pwrseq_debugfs_seq_next() declares 'next' with __free(put_device),
which causes put_device() to be called on the returned pointer when
the variable goes out of scope.  This results in a use-after-free
since the seq_file framework receives a pointer whose reference has
already been dropped.

Simply removing __free(put_device) would fix the UAF but would leak
the reference acquired by bus_find_next_device(), as stop() only
calls up_read(&pwrseq_sem) and never releases the device reference.

Fix this by making the reference counting consistent across all
seq_file callbacks, matching the standard pattern used by PCI and
SCSI:

- start(): use get_device() so it returns a referenced pointer.
- next(): explicitly put_device(curr) to release the previous
  device's reference (no NULL check needed - the seq_file framework
  only calls next() while the previous return was non-NULL).
- stop(): put_device(data) to release the last iterated device's
  reference, with a NULL guard since stop() may be called with NULL
  when start() returned NULL or next() reached end-of-sequence.

## Remediation

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