---
id: CVE-2025-39829
title: 'trace/fgraph: Fix the warning caused by missing unregister notifier'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  trace/fgraph: Fix the warning caused by missing unregister notifier

  This warning was triggered during testing on v6.16:

  notifier callback ftrace_suspend_notifier_call…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: adp
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 <
    aa977309397fe2438801b1ca1ce7bc4106d8e985
  - >-
    Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 <
    2a2deb9f8df70480050351ac27041f19bb9e718b
  - >-
    Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 <
    000aa47a51233fd38a629b029478e0278e1e9fbe
  - >-
    Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 <
    edede7a6dcd7435395cf757d053974aaab6ab1c2
  - Linux 2.6.30
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-01-14T18:17:20.629374Z'
published: '2025-09-16'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:37:24.094Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-39829'
references:
  - url: 'https://git.kernel.org/stable/c/aa977309397fe2438801b1ca1ce7bc4106d8e985'
  - url: 'https://git.kernel.org/stable/c/2a2deb9f8df70480050351ac27041f19bb9e718b'
  - url: 'https://git.kernel.org/stable/c/000aa47a51233fd38a629b029478e0278e1e9fbe'
  - url: 'https://git.kernel.org/stable/c/edede7a6dcd7435395cf757d053974aaab6ab1c2'
tags:
  - cve.org
epss: 0.00189
epssPercentile: 0.08465
ingestedAt: '2026-10-21T12:48:53.689Z'
---

## Overview

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

trace/fgraph: Fix the warning caused by missing unregister notifier

This warning was triggered during testing on v6.16:

notifier callback ftrace_suspend_notifier_call already registered
WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0
...
Call Trace:
 <TASK>
 blocking_notifier_chain_register+0x34/0x60
 register_ftrace_graph+0x330/0x410
 ftrace_profile_write+0x1e9/0x340
 vfs_write+0xf8/0x420
 ? filp_flush+0x8a/0xa0
 ? filp_close+0x1f/0x30
 ? do_dup2+0xaf/0x160
 ksys_write+0x65/0xe0
 do_syscall_64+0xa4/0x260
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

When writing to the function_profile_enabled interface, the notifier was
not unregistered after start_graph_tracing failed, causing a warning the
next time function_profile_enabled was written.

Fixed by adding unregister_pm_notifier in the exception path.

## Affected

- `Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 < aa977309397fe2438801b1ca1ce7bc4106d8e985`
- `Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 < 2a2deb9f8df70480050351ac27041f19bb9e718b`
- `Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 < 000aa47a51233fd38a629b029478e0278e1e9fbe`
- `Linux >= 4a2b8dda3f8705880ec7408135645602d5590f51 < edede7a6dcd7435395cf757d053974aaab6ab1c2`
- `Linux 2.6.30`

## Remediation

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