{"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":"2026-10-06T08:44:50.209Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-06T08:44:50.209Z"},"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-rc4","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-rc4"},{"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"}}}}