SB20261022118 - Improper Check for Unusual or Exceptional Conditions in Linux kernel selftests cgroup

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check for Unusual or Exceptional Conditions (CVE-ID: CVE-2026-98542)

CWE-ID: CWE-754 - Improper Check for Unusual or Exceptional Conditions

CVSSv4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to bypass cpuset CPU exclusivity constraints and create partitions with overlapping exclusive CPU assignments.

The vulnerability exists due to improper handling of conflicting CPU assignments in remote_partition_enable() in kernel/cgroup/cpuset.c when enabling a remote partition beneath an existing local partition through a non-partition intermediate cgroup. A local privileged user can configure a remote partition to claim CPUs already owned by the ancestor local partition because the conflict check emits a warning but allows partition creation to proceed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0751ab665cb3dcdac224b002565f2e28461740d5
• https://git.kernel.org/stable/c/241e67b60308cdce25bba66616a109759edd1d40
• https://git.kernel.org/stable/c/31c88350b7dd1522792f726f79607f31bb55c50f