{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98214", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.325Z", "datePublished": "2026-10-06T08:44:50.209Z", "dateUpdated": "2026-10-19T09:15:45.082Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:15:45.082Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nselinux: recheck intermediate backing files on mprotect()\n\nmprotect() can be used to bypass the SELinux checks that mmap() performs\nagainst the intermediate layers of a stacked filesystem.\n\nmmap() checks every backing layer as the request descends through the\nstack. mprotect() only has the lowest backing file in vma->vm_file, so it\nrechecks the top-level user and the lowest mounter, but skips the mounters\nof every layer in between. With two nested overlayfs mounts and a policy\ndenying mounter_t -> middle_file_t:file { execute }, a direct\nmmap(PROT_EXEC) is denied:\n\n avc: denied { execute } for pid=71 comm=\"nested_exec\"\n path=\"/payload\" dev=\"overlay\" ino=9\n scontext=user_u:base_r:mounter_t\n tcontext=user_u:object_r:middle_file_t tclass=file permissive=0\n\nwhile mmap(PROT_NONE) followed by mprotect(PROT_EXEC) succeeds.\n\nPreserve each intermediate path, mounter SID and file-description SID in\nthe backing-file security blob, copying the saved entries when another\nbacking layer is opened. Allocate the array only for nested backing files,\nand release it and the path references in the backing_file_free hook.\n\nDuring mprotect(), recheck fd { use } and the requested inode permissions\nfor every saved mounter, and include the intermediate layers in the execmod\nchecks. Policy for nested stacking may then need to grant intermediate\nmounters what a direct mmap() already requires, and execmod on intermediate\nlabels for binaries using text relocations.\n\nTested on arm64 QEMU with a small BusyBox initramfs and a purpose-built\nSELinux policy, on a mainline tree containing\ncommit f2381b546e7e (\"fs: fix user path of nested backing files\").\n\n[PM: subject tweak]" } ], "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": "4d50ebe5a27724e020747ffd61a051dec67cb8ec", "status": "affected", "versionType": "git" }, { "version": "8bacd09f12c27710228562e4d13163e58c5f4a45", "lessThan": "89376fbfdcc1a728e1775f98752cdd90b0930a00", "status": "affected", "versionType": "git" }, { "version": "d844702198395d3f80222777030f69db6be6b709", "lessThan": "d127c7e1f3e1231d8ac8b2738e3f00bea12afe74", "status": "affected", "versionType": "git" }, { "version": "82544d36b1729153c8aeb179e84750f0c085d3b1", "lessThan": "c2bbb905af2293549651b614a52ad91e0b462b60", "status": "affected", "versionType": "git" }, { "version": "82544d36b1729153c8aeb179e84750f0c085d3b1", "lessThan": "78fc54b934bfb2c18aad8154c7302067146946f9", "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/4d50ebe5a27724e020747ffd61a051dec67cb8ec" }, { "url": "https://git.kernel.org/stable/c/89376fbfdcc1a728e1775f98752cdd90b0930a00" }, { "url": "https://git.kernel.org/stable/c/d127c7e1f3e1231d8ac8b2738e3f00bea12afe74" }, { "url": "https://git.kernel.org/stable/c/c2bbb905af2293549651b614a52ad91e0b462b60" }, { "url": "https://git.kernel.org/stable/c/78fc54b934bfb2c18aad8154c7302067146946f9" } ], "title": "selinux: recheck intermediate backing files on mprotect()", "x_generator": { "engine": "bippy-1.2.0" } } } }