PT-2025-8852 · Linux · Linux Kernel

Published 2025-02-27 · Updated 2025-02-28 · CVE-2025-21740

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A bug in the Linux kernel has been identified, related to the KVM x86/mmu module. The issue occurs when waking a VM's NX huge page recovery thread, where the thread's existence is not verified before attempting to wake it. This can lead to a kernel NULL pointer dereference. The error is associated with a supervisor read access in kernel mode and a not-present page error. The problem is triggered by a specific sequence of events involving the vhost task wake function and the set nx huge pages function within the KVM module.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2025-21740

Affected Products

Linux Kernel

References · 11

• https://security-tracker.debian.org/tracker/CVE-2025-21740 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-21740 · Security Note
• https://osv.dev/vulnerability/CVE-2025-21740 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21740 · Vendor Advisory
• https://git.kernel.org/stable/c/2b3928b7c896e5a9fb6b1373924adafe8e01a0c6 · Patch
• https://git.kernel.org/stable/c/43fb96ae78551d7bfa4ecca956b258f085d67c40 · Patch
• https://cve.org/CVERecord?id=CVE-2025-21740 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-21740 · Vendor Advisory
• https://git.kernel.org/stable/c/974f85f1f7eb7dc7fce0988046e06eeccab576a7 · Patch
• https://git.kernel.org/linus/43fb96ae78551d7bfa4ecca956b258f085d67c40 · Note
• https://twitter.com/CVEnew/status/1895260275495825718 · Twitter Post