---
id: CVE-2026-98816
title: 'bpf: Fix overflow of jump offset in constant blinding'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Fix overflow of jump offset in constant blinding

  bpf_jit_blind_insn() rewrites 'if rX op imm goto off' into:

    AX = imm ^ rnd
    AX ^= rnd
    if rX op AX goto off
  …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4f3446bb809f20ad56cadf712e6006815ae7a8f9 <
    443328237113ee0ea515e506497334d871dbc2aa
  - >-
    Linux >= 4f3446bb809f20ad56cadf712e6006815ae7a8f9 <
    ad139384ecddb6f3e7e3c3c12765aafae0e39670
  - Linux 4.7
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:49:05.616Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98816'
references:
  - url: 'https://git.kernel.org/stable/c/443328237113ee0ea515e506497334d871dbc2aa'
  - url: 'https://git.kernel.org/stable/c/ad139384ecddb6f3e7e3c3c12765aafae0e39670'
tags:
  - cve.org
ingestedAt: '2026-10-18T16:47:32.476Z'
---

## Overview

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

bpf: Fix overflow of jump offset in constant blinding

bpf_jit_blind_insn() rewrites 'if rX op imm goto off' into:

  AX = imm ^ rnd
  AX ^= rnd
  if rX op AX goto off

and subtracts 2 from off when the jump is backward. off is s16, so
-32767 and -32768 wrap and the jump goes 32767 insns forward, past the
end of the prog. The jump is inside the patch, hence bpf_adj_branches()
doesn't check it. The kernel crashes when such prog runs with
bpf_jit_harden=2.

Return -ERANGE in such case. bpf_jit_blind_constants() fails the same
way when blinding of other insns moves a jump out of range.

## Affected

- `Linux >= 4f3446bb809f20ad56cadf712e6006815ae7a8f9 < 443328237113ee0ea515e506497334d871dbc2aa`
- `Linux >= 4f3446bb809f20ad56cadf712e6006815ae7a8f9 < ad139384ecddb6f3e7e3c3c12765aafae0e39670`
- `Linux 4.7`

## Remediation

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