{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-98542",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:25:14.356Z",
        "datePublished": "2026-10-18T15:18:10.035Z",
        "dateUpdated": "2026-10-19T09:21:25.599Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T09:21:25.599Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict\n\nWhen a remote partition is created underneath an existing local partition\nvia a non-partition (PRS_MEMBER) intermediate cgroup, update_prstate() sees\nparent->partition_root_state == PRS_MEMBER and calls\nremote_partition_enable().\n\nCommit 86888c7bd117 (\"cgroup/cpuset: Add warnings to catch inconsistency\nin exclusive CPUs\") replaced the cpumask_intersects(tmp->new_cpus,\nsubpartitions_cpus) error check in remote_partition_enable() with\nWARN_ON_ONCE(). As a result, remote_partition_enable() emits a warning\nand proceeds to enable the remote partition on CPUs that are already\nowned by the ancestor local partition in subpartitions_cpus.\n\nThis can be reproduced on Linux 7.3.0-rc3 with:\n\n  mkdir -p /tmp/cg1\n  mount -t cgroup2 none /tmp/cg1\n  echo \"+cpuset\" > /tmp/cg1/cgroup.subtree_control\n\n  mkdir /tmp/cg1/A\n  echo 1 > /tmp/cg1/A/cpuset.cpus\n  echo 1 > /tmp/cg1/A/cpuset.cpus.exclusive\n  echo root > /tmp/cg1/A/cpuset.cpus.partition\n  echo \"+cpuset\" > /tmp/cg1/A/cgroup.subtree_control\n\n  mkdir /tmp/cg1/A/B\n  echo 1 > /tmp/cg1/A/B/cpuset.cpus\n  echo 1 > /tmp/cg1/A/B/cpuset.cpus.exclusive\n  echo \"+cpuset\" > /tmp/cg1/A/B/cgroup.subtree_control\n\n  mkdir /tmp/cg1/A/B/D\n  echo 1 > /tmp/cg1/A/B/D/cpuset.cpus\n  echo 1 > /tmp/cg1/A/B/D/cpuset.cpus.exclusive\n  echo root > /tmp/cg1/A/B/D/cpuset.cpus.partition\n\nwhich triggers:\n\n  WARNING: kernel/cgroup/cpuset.c:1594 at remote_partition_enable+0x1c1/0x300\n\nand leaves both /tmp/cg1/A and /tmp/cg1/A/B/D as active root partitions\nclaiming exclusive CPU 1.\n\nFix this by returning PERR_NOCPUS when tmp->new_cpus intersects\nsubpartitions_cpus in remote_partition_enable(), matching the error code\nused by remote_cpus_update() for the same subpartitions_cpus conflict, and\nadd a regression test case to\ntools/testing/selftests/cgroup/test_cpuset_prs.sh.\n\nTested in QEMU on Linux 7.3.0-rc3 using the reproducer above and\ntools/testing/selftests/cgroup/test_cpuset_prs.sh."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/cgroup/cpuset.c",
                        "tools/testing/selftests/cgroup/test_cpuset_prs.sh"
                    ],
                    "versions": [
                        {
                            "version": "86888c7bd117c29eab169c37e5f6bbbf583da983",
                            "lessThan": "241e67b60308cdce25bba66616a109759edd1d40",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "86888c7bd117c29eab169c37e5f6bbbf583da983",
                            "lessThan": "0751ab665cb3dcdac224b002565f2e28461740d5",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "86888c7bd117c29eab169c37e5f6bbbf583da983",
                            "lessThan": "31c88350b7dd1522792f726f79607f31bb55c50f",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/cgroup/cpuset.c",
                        "tools/testing/selftests/cgroup/test_cpuset_prs.sh"
                    ],
                    "versions": [
                        {
                            "version": "6.16",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.16",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.55",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.9",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "6.18.55"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "7.2.9"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/241e67b60308cdce25bba66616a109759edd1d40"
                },
                {
                    "url": "https://git.kernel.org/stable/c/0751ab665cb3dcdac224b002565f2e28461740d5"
                },
                {
                    "url": "https://git.kernel.org/stable/c/31c88350b7dd1522792f726f79607f31bb55c50f"
                }
            ],
            "title": "cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}