---
id: CVE-2021-46908
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Use correct permission flag for mixed signed bounds arithmetic

  We forbid adding unknown scalars with mixed signed bounds due to the
  spectre v1 masking mitigation.…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Use correct permission flag for mixed signed bounds arithmetic

  We forbid adding unknown scalars with mixed signed bounds due to the
  spectre v1 masking mitigation.…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.8.0, < 5.10.32'
  - 'linux_kernel >= 5.11.0, < 5.11.16'
patched:
  - linux_kernel 5.11.16
published: '2024-02-27'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-46908'
references:
  - url: 'https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00241
epssPercentile: 0.13504
ingestedAt: '2026-08-04T10:39:38.135Z'
---

## Overview

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

bpf: Use correct permission flag for mixed signed bounds arithmetic

We forbid adding unknown scalars with mixed signed bounds due to the
spectre v1 masking mitigation. Hence this also needs bypass_spec_v1
flag instead of allow_ptr_leaks.

## Affected

- `linux_kernel >= 5.8.0, < 5.10.32`
- `linux_kernel >= 5.11.0, < 5.11.16`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.11.16`