CVE-2022-49562

5.5 MEDIUM
Published: February 26, 2025 Modified: October 22, 2025

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits Use the recently introduced __try_cmpxchg_user() to update guest PTE A/D bits instead of mapping the PTE into kernel address space. The VM_PFNMAP path is broken as it assumes that vm_pgoff is the base pfn of the mapped VMA range, which is conceptually wrong as vm_pgoff is the offset relative to the file and has nothing to do with the pfn. The horrific hack worked for the original use case (backing guest memory with /dev/mem), but leads to accessing "random" pfns for pretty much any other VM_PFNMAP case.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://git.kernel.org/stable/c/38b888911e8dc89b89d8147cfb1d2dbe6373bf78
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/8089e5e1d18402fb8152d6b6815450a36fffa9b0
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/f122dfe4476890d60b8c679128cd2259ec96a24c
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.5 / 10.0
EPSS (Exploit Probability)
0.0%
11th percentile
Exploitation Status
Not in CISA KEV

Affected Vendors

linux