PT-2026-38982 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-21 · CVE-2026-43331

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 In the x86 architecture, the load segments() function modifies segment registers, which invalidates the GS base used by KCOV for per-cpu data. When CONFIG KCOV is enabled, any subsequent instrumented C code call, such as native gdt invalidate(), causes the kernel to crash in an endless loop. This issue occurs during kexec operations on a KCOV-instrumented kernel, specifically in scenarios like enabling crash dump collection in syzkaller where both CONFIG KEXEC and CONFIG KCOV are enabled simultaneously.

Recommendations Disable KCOV instrumentation for the machine kexec 64.c and physaddr.c files.

Fix

Related Identifiers

CVE-2026-43331

Affected Products

Linux Kernel

References · 14

• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43331 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43331 · Security Note
• https://cve.org/CVERecord?id=CVE-2026-43331 · Security Note
• https://osv.dev/vulnerability/BELL-CVE-2026-43331 · Vendor Advisory
• https://git.kernel.org/stable/c/1e3e98596c2769721ade0418434852fb3af4849a · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43331 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43331 · Vendor Advisory
• https://git.kernel.org/stable/c/917e3ad3321e75ca0223d5ccf26ceda116aa51e1 · Patch
• https://security-tracker.debian.org/tracker/CVE-2026-43331 · Vendor Advisory
• https://git.kernel.org/stable/c/de05c66fab8847237a9ca216934e56d3ee837f08 · Patch
• https://docs.bell-sw.com/security/cves/CVE-2026-43331 · Note
• https://git.kernel.org/linus/917e3ad3321e75ca0223d5ccf26ceda116aa51e1 · Note
• https://twitter.com/CVEnew/status/2052811051561824530 · Twitter Post
• https://twitter.com/infoflowcloud/status/2052812382989087002 · Twitter Post