{"schema":"threatline.record/2","record":{"id":"CVE-2026-98214","aliases":[],"summary":"selinux: recheck intermediate backing files on mprotect()","details":"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]","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","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"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","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"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"4d50ebe5a27724e020747ffd61a051dec67cb8ec","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"89376fbfdcc1a728e1775f98752cdd90b0930a00","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"78fc54b934bfb2c18aad8154c7302067146946f9","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.6.158","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.12.112","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6.18.54","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","source_modified_at":"2026-10-19T09:15:45.082Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7.1","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00219,"percentile":0.11747,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:44:50.209Z","modified_at":"2026-10-19T09:15:45.082Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98214","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:15:45.082Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98214","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/4d50ebe5a27724e020747ffd61a051dec67cb8ec"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/89376fbfdcc1a728e1775f98752cdd90b0930a00"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/d127c7e1f3e1231d8ac8b2738e3f00bea12afe74"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/c2bbb905af2293549651b614a52ad91e0b462b60"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/78fc54b934bfb2c18aad8154c7302067146946f9"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:15:45.082Z","content_hash":"343ba30fde5da54908bd4abef6c54e7a12a40cec70065aabd8e17a0e8a1dac7f"}}