PT-2026-38970 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-15 · CVE-2026-43319

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 lock inversion exists in the spidev driver involving two mutexes, spi lock and buf lock. These locks were acquired in different orders depending on the execution path: write() and read() functions acquired buf lock then spi lock, while the ioctl() function acquired spi lock then buf lock. This AB-BA locking pattern can lead to circular locking dependencies and deadlocks, causing the SPI system to hang. The issue is triggered when a userspace program performs write() and SPI IOC WR MAX SPEED HZ ioctl() calls from separate threads on the same spidev file descriptor.

Recommendations Update the Linux kernel to a version where the buf lock has been removed and the locking model simplified to use only spi lock for serializing access.

Fix

Improper Locking

Weakness Enumeration

CWE-667

Related Identifiers

CVE-2026-43319

Affected Products

Linux Kernel

References · 18

• https://security-tracker.debian.org/tracker/CVE-2026-43319 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43319 · Security Note
• https://git.kernel.org/stable/c/e341e18215030af2136836b78508e0d798916df7 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43319 · Vendor Advisory
• https://git.kernel.org/stable/c/41ccfac7d302968a4f32b5f7b012d066c5f5cdf8 · Patch
• https://git.kernel.org/stable/c/f8431b8672231d378b03176fe74c95adfd3522cf · Patch
• https://osv.dev/vulnerability/BELL-CVE-2026-43319 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-43319 · Security Note
• https://git.kernel.org/stable/c/40534d19ed2afb880ecf202dab26a8e7a5808d16 · Patch
• https://ubuntu.com/security/CVE-2026-43319 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43319 · Vendor Advisory
• https://twitter.com/infoflowcloud/status/2053133191775396256 · Twitter Post
• https://twitter.com/windowsforum/status/2053767966341128211 · Twitter Post
• https://twitter.com/hetmehtaa/status/2055151398283837677 · Twitter Post
• https://git.kernel.org/linus/40534d19ed2afb880ecf202dab26a8e7a5808d16 · Note