{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-40212", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.179Z", "datePublished": "2025-11-24T13:04:20.888Z", "dateUpdated": "2025-12-01T06:20:17.962Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-12-01T06:20:17.962Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix refcount leak in nfsd_set_fh_dentry()\n\nnfsd exports a \"pseudo root filesystem\" which is used by NFSv4 to find\nthe various exported filesystems using LOOKUP requests from a known root\nfilehandle. NFSv3 uses the MOUNT protocol to find those exported\nfilesystems and so is not given access to the pseudo root filesystem.\n\nIf a v3 (or v2) client uses a filehandle from that filesystem,\nnfsd_set_fh_dentry() will report an error, but still stores the export\nin \"struct svc_fh\" even though it also drops the reference (exp_put()).\nThis means that when fh_put() is called an extra reference will be dropped\nwhich can lead to use-after-free and possible denial of service.\n\nNormal NFS usage will not provide a pseudo-root filehandle to a v3\nclient. This bug can only be triggered by the client synthesising an\nincorrect filehandle.\n\nTo fix this we move the assignments to the svc_fh later, after all\npossible error cases have been detected."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/nfsfh.c"], "versions": [{"version": "ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444", "lessThan": "b6bc86ce3944b10b9fc181fc00c1a520a20ed965", "status": "affected", "versionType": "git"}, {"version": "ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444", "lessThan": "c83d7365cec5eb5ebeeee2a72e29b4ca58a7e4c2", "status": "affected", "versionType": "git"}, {"version": "ef7f6c4904d03ccd7478e1ac20ed75f79c4ac444", "lessThan": "8a7348a9ed70bda1c1f51d3f1815bcbdf9f3b38c", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/nfsfh.c"], "versions": [{"version": "6.12", "status": "affected"}, {"version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.59", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17.9", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18", "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": "6.12", "versionEndExcluding": "6.12.59"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.17.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b6bc86ce3944b10b9fc181fc00c1a520a20ed965"}, {"url": "https://git.kernel.org/stable/c/c83d7365cec5eb5ebeeee2a72e29b4ca58a7e4c2"}, {"url": "https://git.kernel.org/stable/c/8a7348a9ed70bda1c1f51d3f1815bcbdf9f3b38c"}], "title": "nfsd: fix refcount leak in nfsd_set_fh_dentry()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix refcount leak in nfsd_set_fh_dentry()\n\nnfsd exports a \"pseudo root filesystem\" which is used by NFSv4 to find\nthe various exported filesystems using LOOKUP requests from a known root\nfilehandle. NFSv3 uses the MOUNT protocol to find those exported\nfilesystems and so is not given access to the pseudo root filesystem.\n\nIf a v3 (or v2) client uses a filehandle from that filesystem,\nnfsd_set_fh_dentry() will report an error, but still stores the export\nin \"struct svc_fh\" even though it also drops the reference (exp_put()).\nThis means that when fh_put() is called an extra reference will be dropped\nwhich can lead to use-after-free and possible denial of service.\n\nNormal NFS usage will not provide a pseudo-root filehandle to a v3\nclient. This bug can only be triggered by the client synthesising an\nincorrect filehandle.\n\nTo fix this we move the assignments to the svc_fh later, after all\npossible error cases have been detected."}], "id": "CVE-2025-40212", "lastModified": "2025-11-25T22:16:16.690", "metrics": {}, "published": "2025-11-24T13:16:02.813", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8a7348a9ed70bda1c1f51d3f1815bcbdf9f3b38c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b6bc86ce3944b10b9fc181fc00c1a520a20ed965"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c83d7365cec5eb5ebeeee2a72e29b4ca58a7e4c2"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: nfsd: fix refcount leak in nfsd_set_fh_dentry()", "id": "2416750", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2416750"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2025-40212", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-11-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-40212\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-40212\nhttps://lore.kernel.org/linux-cve-announce/2025112424-CVE-2025-40212-e33b@gregkh/T"], "threat_severity": "Important"}