In the Linux kernel, the following vulnerability has been resolved:

cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode()

After seeing the patch [1] to guard is_in_v2_mode() with RCU, it makes
me realize that is_in_v2_mode() may be called in a context where a new
cgroup filesystem is being rebound with stale cpuset_cgrp_subsys.root
pointer. Avoid this potential UaF situation by adding a new cpuset_v2_mode
flag which is set when the cpuset_v2_mode mount option is used. This
flag is written into only when cpuset_bind() is being called with a
stable cpuset_cgrp_subsys.root value. The is_in_v2_mode() helper is
modified to read the new cpuset_v2_mode flag instead of accessing
cpuset_cgrp_subsys.root directly.

[1] https://lore.kernel.org/lkml/[email protected]
Advisories

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Fixes

Solution

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Workaround

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History

Fri, 23 Oct 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux linux
Vendors & Products Linux linux

Fri, 23 Oct 2026 12:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode() After seeing the patch [1] to guard is_in_v2_mode() with RCU, it makes me realize that is_in_v2_mode() may be called in a context where a new cgroup filesystem is being rebound with stale cpuset_cgrp_subsys.root pointer. Avoid this potential UaF situation by adding a new cpuset_v2_mode flag which is set when the cpuset_v2_mode mount option is used. This flag is written into only when cpuset_bind() is being called with a stable cpuset_cgrp_subsys.root value. The is_in_v2_mode() helper is modified to read the new cpuset_v2_mode flag instead of accessing cpuset_cgrp_subsys.root directly. [1] https://lore.kernel.org/lkml/[email protected]
Title cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-23T12:19:45.458Z

Reserved: 2026-09-25T10:25:14.383Z

Link: CVE-2026-98972

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-23T13:17:18.783

Modified: 2026-10-23T13:17:18.783

Link: CVE-2026-98972

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T17:30:16Z

Weaknesses

No weakness.