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CVE-2026-98972

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

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in988bf67a13890a37a33201f95947095ca9bec856Fixed versionCVE List
Published23 Oct 2026Updated 23 Oct 2026CVE List

What fixes it

  • 988bf67a13890a37a33201f95947095ca9bec856LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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/20260929084124.626693-2-arighi@nvidia.com

Text from CVE List

Affected versions 6

  • Linuxaffected: b8d1b8ee93df8ffbabbeadd65d39853cfad6d698 before 988bf67a13890a37a33201f95947095ca9bec856CVE List
  • Linuxaffected: b8d1b8ee93df8ffbabbeadd65d39853cfad6d698 before e06b678e3b4e12fdaa0b51a7a5a54abc5dbd6469CVE List
  • Linuxaffected: 4.14CVE List
  • Linuxunaffected: all versions before 4.14CVE List
  • Linuxunaffected: 7.2.11 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 2