---
id: CVE-2022-49556
title: 'KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak

  For some sev ioctl interfaces, the length parameter that is passed maybe
  less than or equal …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 <
    401bef1f95de92c3a8c6eece46e02fa88d7285ee
  - >-
    Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 <
    d8fdb4b24097472ff6b3c0559448200d420b1418
  - >-
    Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 <
    bbdcc644b59e01e98c68894a9fab42b9687f42b0
  - >-
    Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 <
    57a01725339f9d82b099102ba2751621b1caab93
  - >-
    Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 <
    d22d2474e3953996f03528b84b7f52cc26a39403
  - Linux 5.7
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:46:11.191593Z'
published: '2025-02-26'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T19:49:40.531Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49556'
references:
  - url: 'https://git.kernel.org/stable/c/401bef1f95de92c3a8c6eece46e02fa88d7285ee'
  - url: 'https://git.kernel.org/stable/c/d8fdb4b24097472ff6b3c0559448200d420b1418'
  - url: 'https://git.kernel.org/stable/c/bbdcc644b59e01e98c68894a9fab42b9687f42b0'
  - url: 'https://git.kernel.org/stable/c/57a01725339f9d82b099102ba2751621b1caab93'
  - url: 'https://git.kernel.org/stable/c/d22d2474e3953996f03528b84b7f52cc26a39403'
tags:
  - cve.org
epss: 0.00275
epssPercentile: 0.20062
ingestedAt: '2026-11-05T22:38:31.578Z'
---

## Overview

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

KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak

For some sev ioctl interfaces, the length parameter that is passed maybe
less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data
that PSP firmware returns. In this case, kmalloc will allocate memory
that is the size of the input rather than the size of the data.
Since PSP firmware doesn't fully overwrite the allocated buffer, these
sev ioctl interface may return uninitialized kernel slab memory.

## Affected

- `Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 < 401bef1f95de92c3a8c6eece46e02fa88d7285ee`
- `Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 < d8fdb4b24097472ff6b3c0559448200d420b1418`
- `Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 < bbdcc644b59e01e98c68894a9fab42b9687f42b0`
- `Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 < 57a01725339f9d82b099102ba2751621b1caab93`
- `Linux >= eaf78265a4ab33935d3a0f1407ce4a91aac4d4d5 < d22d2474e3953996f03528b84b7f52cc26a39403`
- `Linux 5.7`

## Remediation

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