---
id: CVE-2026-93045
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Reject arena frees below the arena base

  bpf_arena_free_pages() accepts scalar arena addresses
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Reject arena frees below the arena base

  bpf_arena_free_pages() accepts scalar arena addresses. The runtime
  masks the address to the low 32 bits and reconstructs a…
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 >= 317460317a02a1af512697e6e964298dedd8a163 <
    90453eaf8f14e7be0ab03983f2a93aeb6b990a58
  - >-
    Linux >= 317460317a02a1af512697e6e964298dedd8a163 <
    a968dffa5ab3c74d2ebb3a6233bf8b843f0bfc20
  - >-
    Linux >= 317460317a02a1af512697e6e964298dedd8a163 <
    8a08635656037aee9c12231ed384449c4ffb1a93
  - >-
    Linux >= 317460317a02a1af512697e6e964298dedd8a163 <
    b5a71cb2db6d84ac0042549dcec266b18429d41e
  - Linux 6.9
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:18:19.097'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93045'
references:
  - url: 'https://git.kernel.org/stable/c/8a08635656037aee9c12231ed384449c4ffb1a93'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/90453eaf8f14e7be0ab03983f2a93aeb6b990a58'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a968dffa5ab3c74d2ebb3a6233bf8b843f0bfc20'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b5a71cb2db6d84ac0042549dcec266b18429d41e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00129
epssPercentile: 0.02866
ingestedAt: '2026-09-17T16:21:47.773Z'
---

## Overview

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

bpf: Reject arena frees below the arena base

bpf_arena_free_pages() accepts scalar arena addresses. The runtime
masks the address to the low 32 bits and reconstructs a full user
address from the arena base before returning the range to the arena
free tree.

When the scalar value is below the low 32 bits of the arena base,
full_uaddr falls below user_vm_start. The existing upper-end clipping
then turns this into an out-of-range free-tree offset. A later
allocation can reuse that offset and return an address below the arena
mapping.

Reject such frees before computing the clipped range.

## Remediation

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