PT-2026-34361 · Linux · Linux Kernel

Published 2026-04-22 · Updated 2026-04-23 · CVE-2026-31456

Positive Technologies (AI Summary)

CVSS v3.1

4.7

Medium

Base vector

AV:L/AC:H/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 race condition exists in the Linux kernel between a concurrent split and refault of a PUD entry. Specifically, the splitting of a PUD entry in the walk pud range() function can race with a concurrent thread refaulting the PUD leaf entry. This can cause the system to attempt walking a PMD range that has disappeared, potentially triggering a kernel BUG and a page fault. This issue can be reproduced by reading numa maps of a process while VFIO-PCI is setting up DMA via the vfio pin pages remote call on a large BAR for that process.

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

Race Condition

Weakness Enumeration

CWE-362

Related Identifiers

CVE-2026-31456

Affected Products

Linux Kernel

References · 14

• https://osv.dev/vulnerability/BELL-CVE-2026-31456 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-31456 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-31456 · Vendor Advisory
• https://git.kernel.org/stable/c/3b89863c3fa482912911cd65a12a3aeef662c250 · Patch
• https://git.kernel.org/stable/c/38ec58670a0c5fc1edabdeccd857e586b7b3f318 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-31456 · Vendor Advisory
• https://git.kernel.org/stable/c/9bbbebd94dd5be25ec8c899d46ef01b33d5d22c0 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-31456 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-31456 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-31456 · Security Note
• https://twitter.com/vuldb/status/2046980136218788122 · Twitter Post
• https://docs.bell-sw.com/security/cves/CVE-2026-31456 · Note
• https://twitter.com/CVEnew/status/2046980032954802332 · Twitter Post
• https://git.kernel.org/linus/3b89863c3fa482912911cd65a12a3aeef662c250 · Note