---
id: CVE-2026-97443
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  perf/ftrace: Fix WARNING in __unregister_ftrace_function

  perf_ftrace_function_unregister() unconditionally calls
  unregister_ftrace_function() without checking whether …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  perf/ftrace: Fix WARNING in __unregister_ftrace_function

  perf_ftrace_function_unregister() unconditionally calls
  unregister_ftrace_function() without checking whether …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    df097713b56ffac5eed32a9be2e7d27ac48d9087
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    7f845820afaad339341c2ae42bc7fdec175df9ea
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    9581123304b23049437324038698af9fb56ee663
  - Linux < 6.12.111
  - Linux < 6.18.53
  - Linux (all versions)
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T17:17:22.550'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97443'
references:
  - url: 'https://git.kernel.org/stable/c/7f845820afaad339341c2ae42bc7fdec175df9ea'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9581123304b23049437324038698af9fb56ee663'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/df097713b56ffac5eed32a9be2e7d27ac48d9087'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-24T16:47:15.877Z'
---

## Overview

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

perf/ftrace: Fix WARNING in __unregister_ftrace_function

perf_ftrace_function_unregister() unconditionally calls
unregister_ftrace_function() without checking whether the ftrace_ops
was ever successfully registered. This triggers a WARN_ON in
__unregister_ftrace_function() when the ops doesn't have
FTRACE_OPS_FL_ENABLED set.

This can happen during perf_event_alloc() error cleanup when
perf_trace_destroy() is called via __free_event() on an event whose
ftrace_ops registration failed or was already torn down by
perf_try_init_event()'s err_destroy path.

The call path is:
  perf_event_alloc() error cleanup
    -> __free_event()
      -> event->destroy() [tp_perf_event_destroy]
        -> perf_trace_destroy()
          -> perf_trace_event_close()
            -> TRACE_REG_PERF_CLOSE
              -> perf_ftrace_function_unregister()
                -> unregister_ftrace_function()
                  -> __unregister_ftrace_function()
                    -> WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))

Fix this by checking FTRACE_OPS_FL_ENABLED before attempting to
unregister. If the ops is not enabled, just free the filter and
return success.

## Remediation

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