---
id: CVE-2023-53557
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fprobe: Release rethook after the ftrace_ops is unregistered

  While running bpf selftests it's possible to get following fault:

    general protection fault, probably fo…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fprobe: Release rethook after the ftrace_ops is unregistered

  While running bpf selftests it's possible to get following fault:

    general protection fault, probably fo…
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'
cwe:
  - CWE-366
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.18, < 6.1.40'
  - 'linux_kernel >= 6.2, < 6.4.5'
  - linux_kernel = 6.5
patched:
  - linux_kernel 6.4.5
published: '2025-10-04'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:17:42.753'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-53557'
references:
  - url: 'https://git.kernel.org/stable/c/03d63255a5783243c110aec5e6ae2f1475c3be76'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5f81018753dfd4989e33ece1f0cb6b8aae498b82'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ce3ec57faff559ccae1e0150c1f077eb2df648a4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53557.json
  - url: 'https://access.redhat.com/security/cve/CVE-2023-53557'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2401471'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2023-53557'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2023-53557'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2025100449-CVE-2023-53557-e7ba@gregkh/T
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00154
epssPercentile: 0.0451
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:35:33.359468Z'
scores:
  nvd: 7.8
  vendor: 5.5
  cna: 7.8
ingestedAt: '2026-10-15T22:48:25.408Z'
---

## Overview

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

fprobe: Release rethook after the ftrace_ops is unregistered

While running bpf selftests it's possible to get following fault:

  general protection fault, probably for non-canonical address \
  0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
  ...
  Call Trace:
   <TASK>
   fprobe_handler+0xc1/0x270
   ? __pfx_bpf_testmod_init+0x10/0x10
   ? __pfx_bpf_testmod_init+0x10/0x10
   ? bpf_fentry_test1+0x5/0x10
   ? bpf_fentry_test1+0x5/0x10
   ? bpf_testmod_init+0x22/0x80
   ? do_one_initcall+0x63/0x2e0
   ? rcu_is_watching+0xd/0x40
   ? kmalloc_trace+0xaf/0xc0
   ? do_init_module+0x60/0x250
   ? __do_sys_finit_module+0xac/0x120
   ? do_syscall_64+0x37/0x90
   ? entry_SYSCALL_64_after_hwframe+0x72/0xdc
   </TASK>

In unregister_fprobe function we can't release fp->rethook while it's
possible there are some of its users still running on another cpu.

Moving rethook_free call after fp->ops is unregistered with
unregister_ftrace_function call.

## Affected

- `linux_kernel >= 5.18, < 6.1.40`
- `linux_kernel >= 6.2, < 6.4.5`
- `linux_kernel = 6.5`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.4.5`

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53557.json)