{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.9-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict  When a remote partition is created underneath an existing local partition via a non-partition (PRS_MEMBER) intermediate cgroup, update_prstate() sees parent-\u003epartition_root_state == PRS_MEMBER and calls remote_partition_enable().  Commit 86888c7bd117 (\"cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs\") replaced the cpumask_intersects(tmp-\u003enew_cpus, subpartitions_cpus) error check in remote_partition_enable() with WARN_ON_ONCE(). As a result, remote_partition_enable() emits a warning and proceeds to enable the remote partition on CPUs that are already owned by the ancestor local partition in subpartitions_cpus.  This can be reproduced on Linux 7.3.0-rc3 with:    mkdir -p /tmp/cg1   mount -t cgroup2 none /tmp/cg1   echo \"+cpuset\" \u003e /tmp/cg1/cgroup.subtree_control    mkdir /tmp/cg1/A   echo 1 \u003e /tmp/cg1/A/cpuset.cpus   echo 1 \u003e /tmp/cg1/A/cpuset.cpus.exclusive   echo root \u003e /tmp/cg1/A/cpuset.cpus.partition   echo \"+cpuset\" \u003e /tmp/cg1/A/cgroup.subtree_control    mkdir /tmp/cg1/A/B   echo 1 \u003e /tmp/cg1/A/B/cpuset.cpus   echo 1 \u003e /tmp/cg1/A/B/cpuset.cpus.exclusive   echo \"+cpuset\" \u003e /tmp/cg1/A/B/cgroup.subtree_control    mkdir /tmp/cg1/A/B/D   echo 1 \u003e /tmp/cg1/A/B/D/cpuset.cpus   echo 1 \u003e /tmp/cg1/A/B/D/cpuset.cpus.exclusive   echo root \u003e /tmp/cg1/A/B/D/cpuset.cpus.partition  which triggers:    WARNING: kernel/cgroup/cpuset.c:1594 at remote_partition_enable+0x1c1/0x300  and leaves both /tmp/cg1/A and /tmp/cg1/A/B/D as active root partitions claiming exclusive CPU 1.  Fix this by returning PERR_NOCPUS when tmp-\u003enew_cpus intersects subpartitions_cpus in remote_partition_enable(), matching the error code used by remote_cpus_update() for the same subpartitions_cpus conflict, and add a regression test case to tools/testing/selftests/cgroup/test_cpuset_prs.sh.  Tested in QEMU on Linux 7.3.0-rc3 using the reproducer above and tools/testing/selftests/cgroup/test_cpuset_prs.sh.",
  "id": "DEBIAN-CVE-2026-98542",
  "modified": "2026-10-19T04:47:24.350127170Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98542"
    }
  ],
  "upstream": [
    "CVE-2026-98542"
  ]
}