{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-98215",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:25:14.326Z",
        "datePublished": "2026-10-06T08:44:51.412Z",
        "dateUpdated": "2026-10-19T09:15:46.038Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T09:15:46.038Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nselinux: preserve user SID across nested backing files\n\nSELinux saves the user file SID in a backing-file security blob so it\nremains available after mmap() replaces vma->vm_file with a backing file.\n\nFor nested backing files (overlayfs over overlayfs, or FUSE passthrough\nbacked by overlayfs), user_file may itself be a backing file.  Its\nfsec->sid is the SID of the mounter that opened it, rather than the user\nthat opened the top-level file.  mprotect() then checks fd { use } against\nthe mounter SID.  This can incorrectly deny access without a domain\ntransition, or check the wrong target SID after one.\n\nCopy the saved user SID when user_file is a backing file.  Keep using the\nregular file SID for the first backing layer.\n\nWith two nested overlayfs mounts and SELinux enforcing,\nmprotect(PROT_READ) returns EACCES with an fd { use } denial against the\nmounter SID.  With this change, mprotect() succeeds.\n\nTested on arm64 QEMU with a small BusyBox initramfs and a purpose-built\nSELinux policy.  The original test was also repeated with Fedora Cloud\nBase 44 userspace and gave the same result."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "security/selinux/hooks.c",
                        "security/selinux/include/objsec.h"
                    ],
                    "versions": [
                        {
                            "version": "bc6c380c1159de52a252ed11f19a42c47f60a735",
                            "lessThan": "caa1b913d90d5dc07073733326d2af0f0288f089",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8bacd09f12c27710228562e4d13163e58c5f4a45",
                            "lessThan": "6aaeec59aadcd1eafc18b049f1b759fb6b9d9569",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "d844702198395d3f80222777030f69db6be6b709",
                            "lessThan": "9d99b770e7b67b00bdef9005b928aad13e1d679b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "82544d36b1729153c8aeb179e84750f0c085d3b1",
                            "lessThan": "ff20d16b2e8230c034e21540043df47222dcc09b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "82544d36b1729153c8aeb179e84750f0c085d3b1",
                            "lessThan": "8c0c602202b9a4909b00bc3354e3c0355bc69e65",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "cd0e707a927a70cdfd8bc5a512a9719a87f5ed51",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6.6.144",
                            "lessThan": "6.6.158",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.95",
                            "lessThan": "6.12.112",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.38",
                            "lessThan": "6.18.54",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.4",
                            "lessThan": "7.1",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "security/selinux/hooks.c",
                        "security/selinux/include/objsec.h"
                    ],
                    "versions": [
                        {
                            "version": "7.1",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.1",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.158",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.112",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.54",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.8",
                            "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": "6.6.144",
                                    "versionEndExcluding": "6.6.158"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.12.95",
                                    "versionEndExcluding": "6.12.112"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.18.38",
                                    "versionEndExcluding": "6.18.54"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.1",
                                    "versionEndExcluding": "7.2.8"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.1",
                                    "versionEndExcluding": "7.3"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.0.4"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/caa1b913d90d5dc07073733326d2af0f0288f089"
                },
                {
                    "url": "https://git.kernel.org/stable/c/6aaeec59aadcd1eafc18b049f1b759fb6b9d9569"
                },
                {
                    "url": "https://git.kernel.org/stable/c/9d99b770e7b67b00bdef9005b928aad13e1d679b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ff20d16b2e8230c034e21540043df47222dcc09b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8c0c602202b9a4909b00bc3354e3c0355bc69e65"
                }
            ],
            "title": "selinux: preserve user SID across nested backing files",
            "x_generator": {
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}