---
id: CVE-2023-54173
title: 'bpf: Disable preemption in bpf_event_output'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Disable preemption in bpf_event_output

  We received report [1] of kernel crash, which is caused by
  using nesting protection without disabled preemption.

  The bpf_e…
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'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb <
    3048cb0dc0cc9dc74ed93690dffef00733bcad5b
  - >-
    Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb <
    c81bdf8f9f2b002d217c3d5357cdea9f2b82ff90
  - >-
    Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb <
    36dd8ca330b76585640ed32255a3c99f901e1502
  - >-
    Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb <
    063c9ce8e74e07bf94f99cd13146f42867875e8b
  - >-
    Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb <
    d62cc390c2e99ae267ffe4b8d7e2e08b6c758c32
  - Linux 5.7
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:38:52.294746Z'
published: '2025-12-30'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T21:41:40.859Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-54173'
references:
  - url: 'https://git.kernel.org/stable/c/3048cb0dc0cc9dc74ed93690dffef00733bcad5b'
  - url: 'https://git.kernel.org/stable/c/c81bdf8f9f2b002d217c3d5357cdea9f2b82ff90'
  - url: 'https://git.kernel.org/stable/c/36dd8ca330b76585640ed32255a3c99f901e1502'
  - url: 'https://git.kernel.org/stable/c/063c9ce8e74e07bf94f99cd13146f42867875e8b'
  - url: 'https://git.kernel.org/stable/c/d62cc390c2e99ae267ffe4b8d7e2e08b6c758c32'
tags:
  - cve.org
epss: 0.00154
epssPercentile: 0.04088
ingestedAt: '2026-10-15T22:48:25.431Z'
---

## Overview

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

bpf: Disable preemption in bpf_event_output

We received report [1] of kernel crash, which is caused by
using nesting protection without disabled preemption.

The bpf_event_output can be called by programs executed by
bpf_prog_run_array_cg function that disabled migration but
keeps preemption enabled.

This can cause task to be preempted by another one inside the
nesting protection and lead eventually to two tasks using same
perf_sample_data buffer and cause crashes like:

  BUG: kernel NULL pointer dereference, address: 0000000000000001
  #PF: supervisor instruction fetch in kernel mode
  #PF: error_code(0x0010) - not-present page
  ...
  ? perf_output_sample+0x12a/0x9a0
  ? finish_task_switch.isra.0+0x81/0x280
  ? perf_event_output+0x66/0xa0
  ? bpf_event_output+0x13a/0x190
  ? bpf_event_output_data+0x22/0x40
  ? bpf_prog_dfc84bbde731b257_cil_sock4_connect+0x40a/0xacb
  ? xa_load+0x87/0xe0
  ? __cgroup_bpf_run_filter_sock_addr+0xc1/0x1a0
  ? release_sock+0x3e/0x90
  ? sk_setsockopt+0x1a1/0x12f0
  ? udp_pre_connect+0x36/0x50
  ? inet_dgram_connect+0x93/0xa0
  ? __sys_connect+0xb4/0xe0
  ? udp_setsockopt+0x27/0x40
  ? __pfx_udp_push_pending_frames+0x10/0x10
  ? __sys_setsockopt+0xdf/0x1a0
  ? __x64_sys_connect+0xf/0x20
  ? do_syscall_64+0x3a/0x90
  ? entry_SYSCALL_64_after_hwframe+0x72/0xdc

Fixing this by disabling preemption in bpf_event_output.

[1] https://github.com/cilium/cilium/issues/26756

## Affected

- `Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb < 3048cb0dc0cc9dc74ed93690dffef00733bcad5b`
- `Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb < c81bdf8f9f2b002d217c3d5357cdea9f2b82ff90`
- `Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb < 36dd8ca330b76585640ed32255a3c99f901e1502`
- `Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb < 063c9ce8e74e07bf94f99cd13146f42867875e8b`
- `Linux >= 2a916f2f546ca1c1e3323e2a4269307f6d9890eb < d62cc390c2e99ae267ffe4b8d7e2e08b6c758c32`
- `Linux 5.7`

## Remediation

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