---
id: CVE-2026-93138
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Fix vmlinux BTF prep race in bpf_get_btf_vmlinux

  bpf_get_btf_vmlinux() lazily parses the vmlinux BTF under the
  bpf_verifier_lock, but publishes the result through…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Fix vmlinux BTF prep race in bpf_get_btf_vmlinux

  bpf_get_btf_vmlinux() lazily parses the vmlinux BTF under the
  bpf_verifier_lock, but publishes the result through…
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'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    f32a4a40bc635be25d6816da4bd91e9e58c31bf3
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    a7fe72d780122eb934536f1719abad445f6afdf7
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    e18a10b39c994f04e1ebd7f8fc042bb1ca8ad053
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    978524ecfc1c539282df5858de1eec20748c6f74
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    eaf302628a78806f66d8224d6ba03fb4d5025de4
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    2892f3f44bf865c8fb6b6c0960edec4cc91806ee
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    86d11c594d60b255b526fa5260f669463fb1a063
  - >-
    Linux >= 8580ac9404f6240668a026785d7d8856f0530409 <
    92863e678070f57c17c868e4bfa2441a5c61ad2b
  - Linux 5.5
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:18:22.363'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93138'
references:
  - url: 'https://git.kernel.org/stable/c/2892f3f44bf865c8fb6b6c0960edec4cc91806ee'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/86d11c594d60b255b526fa5260f669463fb1a063'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/92863e678070f57c17c868e4bfa2441a5c61ad2b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/978524ecfc1c539282df5858de1eec20748c6f74'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a7fe72d780122eb934536f1719abad445f6afdf7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e18a10b39c994f04e1ebd7f8fc042bb1ca8ad053'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eaf302628a78806f66d8224d6ba03fb4d5025de4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f32a4a40bc635be25d6816da4bd91e9e58c31bf3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00176
epssPercentile: 0.06265
ingestedAt: '2026-09-17T16:21:47.748Z'
---

## Overview

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

bpf: Fix vmlinux BTF prep race in bpf_get_btf_vmlinux

bpf_get_btf_vmlinux() lazily parses the vmlinux BTF under the
bpf_verifier_lock, but publishes the result through a plain store
and re-checks it through a plain lockless load. Nothing orders
the stores initializing the struct btf inside btf_parse_vmlinux()
against the store publishing the pointer: On a weakly ordered
arch, a concurrent first-time caller taking the lockless fast
path could in principle observe the pointer before the parsed
contents are visible. The mutex_unlock() does not help such a
reader given it only synchronizes with a later acquisition of the
same lock. Thus, publish the pointer with smp_store_release()
and read it on the fast path with smp_load_acquire().

Acquire semantics are needed rather than a dependency-ordered
READ_ONCE(): btf_parse_vmlinux() also populates globals outside
the returned object (e.g. bpf_ctx_convert.t). An address
dependency would only order accesses performed through the
pointer and not cover other globals.

## Remediation

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