---
id: CVE-2026-72428
title: 'bpf: Fix stack slot index in nospec checks'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Fix stack slot index in nospec checks

  check_stack_write_fixed_off() computes the byte slot for a fixed-offset
  stack write as -off - 1, and records each written by…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0e9280654aa482088ee6ef3deadef331f5ac5fb0 <
    e62268e695075a481a6c4feeb022c19cf57422a6
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    a71eb8f730a91271cf47ce291e785b6b7e54622f
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    ca119656baa8f48a56e0c2f3ab63fdd33ca9e307
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    475405593de2b796224c6297aece44f321195919
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    f1471aa76d74e0df3b2a90731ca0208f498c670b
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    68b41e68a62299f26cb16af422b5c7d1c69dafd9
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    db8f1dcf5950b91886b9df4270bc816370d292c1
  - >-
    Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee <
    d1d53aa30ab3b5ae89161c9cc840b3f7489ad386
  - Linux 872968502114d68c21419cf7eb5ab97717e7b803
  - Linux f5893af2704eb763eb982f01d573f5b19f06b623
  - Linux 0b27bdf02c400684225ee5ee99970bcbf5082282
  - Linux >= 5.10.56 < 5.10.261
  - Linux >= 4.19.207 < 4.20
  - Linux >= 5.4.146 < 5.5
  - Linux >= 5.13.8 < 5.14
  - Linux 5.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:55:08.821846Z'
published: '2026-08-15'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:05:42.172Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72428'
references:
  - url: 'https://git.kernel.org/stable/c/e62268e695075a481a6c4feeb022c19cf57422a6'
  - url: 'https://git.kernel.org/stable/c/a71eb8f730a91271cf47ce291e785b6b7e54622f'
  - url: 'https://git.kernel.org/stable/c/ca119656baa8f48a56e0c2f3ab63fdd33ca9e307'
  - url: 'https://git.kernel.org/stable/c/475405593de2b796224c6297aece44f321195919'
  - url: 'https://git.kernel.org/stable/c/f1471aa76d74e0df3b2a90731ca0208f498c670b'
  - url: 'https://git.kernel.org/stable/c/68b41e68a62299f26cb16af422b5c7d1c69dafd9'
  - url: 'https://git.kernel.org/stable/c/db8f1dcf5950b91886b9df4270bc816370d292c1'
  - url: 'https://git.kernel.org/stable/c/d1d53aa30ab3b5ae89161c9cc840b3f7489ad386'
tags:
  - cve.org
epss: 0.00217
epssPercentile: 0.12245
ingestedAt: '2026-11-06T18:00:12.576Z'
---

## Overview

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

bpf: Fix stack slot index in nospec checks

check_stack_write_fixed_off() computes the byte slot for a fixed-offset
stack write as -off - 1, and records each written byte in slot_type[] with
(slot - i) % BPF_REG_SIZE.

The Spectre v4 sanitization pre-check uses slot_type[i] instead. For a
4-byte write at fp-8 after the lower half of fp-8 has been zeroed, the
pre-check scans bytes 0..3 and sees STACK_ZERO while the actual write updates
bytes 7..4. That can leave the second half-slot write without nospec_result
even though the bytes being overwritten still require sanitization.

Use the same slot index in the sanitization pre-check that the write path uses
when updating slot_type[].

## Affected

- `Linux >= 0e9280654aa482088ee6ef3deadef331f5ac5fb0 < e62268e695075a481a6c4feeb022c19cf57422a6`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < a71eb8f730a91271cf47ce291e785b6b7e54622f`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < ca119656baa8f48a56e0c2f3ab63fdd33ca9e307`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < 475405593de2b796224c6297aece44f321195919`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < f1471aa76d74e0df3b2a90731ca0208f498c670b`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < 68b41e68a62299f26cb16af422b5c7d1c69dafd9`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < db8f1dcf5950b91886b9df4270bc816370d292c1`
- `Linux >= 2039f26f3aca5b0e419b98f65dd36481337b86ee < d1d53aa30ab3b5ae89161c9cc840b3f7489ad386`
- `Linux 872968502114d68c21419cf7eb5ab97717e7b803`
- `Linux f5893af2704eb763eb982f01d573f5b19f06b623`
- `Linux 0b27bdf02c400684225ee5ee99970bcbf5082282`
- `Linux >= 5.10.56 < 5.10.261`
- `Linux >= 4.19.207 < 4.20`
- `Linux >= 5.4.146 < 5.5`
- `Linux >= 5.13.8 < 5.14`
- `Linux 5.14`

## Remediation

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