---
id: CVE-2026-46182
title: 'pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace

  The hdr variable is allocated on the stack and only hdr.version and
  hdr.flags are initialized explic…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= cebdb522fd3edd1fe05f7b4a74a27da7dd0f8d86 <
    0479b6e9f999cc1cbad7d9f09f574fc387e605d5
  - >-
    Linux >= cebdb522fd3edd1fe05f7b4a74a27da7dd0f8d86 <
    f88f8e4485b437e0a2f96a7ff1f88aa22d925659
  - >-
    Linux >= cebdb522fd3edd1fe05f7b4a74a27da7dd0f8d86 <
    cefeed44296261173a806bef988b26bc565da4be
  - Linux 6.18
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:11:21.834383Z'
published: '2026-05-28'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:13:43.452Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-46182'
references:
  - url: 'https://git.kernel.org/stable/c/0479b6e9f999cc1cbad7d9f09f574fc387e605d5'
  - url: 'https://git.kernel.org/stable/c/f88f8e4485b437e0a2f96a7ff1f88aa22d925659'
  - url: 'https://git.kernel.org/stable/c/cefeed44296261173a806bef988b26bc565da4be'
tags:
  - cve.org
epss: 0.00126
epssPercentile: 0.02322
ingestedAt: '2026-11-06T16:57:43.327Z'
---

## Overview

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

pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace

The hdr variable is allocated on the stack and only hdr.version and
hdr.flags are initialized explicitly. Because the struct papr_hvpipe_hdr
contains reserved padding bytes (reserved[3] and reserved2[40]), these
could leak the uninitialized bytes to userspace after copy_to_user().

This patch fixes that by initializing the whole struct to 0.

## Affected

- `Linux >= cebdb522fd3edd1fe05f7b4a74a27da7dd0f8d86 < 0479b6e9f999cc1cbad7d9f09f574fc387e605d5`
- `Linux >= cebdb522fd3edd1fe05f7b4a74a27da7dd0f8d86 < f88f8e4485b437e0a2f96a7ff1f88aa22d925659`
- `Linux >= cebdb522fd3edd1fe05f7b4a74a27da7dd0f8d86 < cefeed44296261173a806bef988b26bc565da4be`
- `Linux 6.18`

## Remediation

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