{"id":"CVE-2023-53381","state":"PUBLISHED","title":"NFSD: fix leaked reference count of nfsd4_ssc_umount_item","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix leaked reference count of nfsd4_ssc_umount_item\n\nThe reference count of nfsd4_ssc_umount_item is not decremented\non error conditions. This prevents the laundromat from unmounting\nthe vfsmount of the source file.\n\nThis patch decrements the reference count of nfsd4_ssc_umount_item\non error.","publishedAt":"2025-09-18T13:33:26.234Z","updatedAt":"2026-08-05T09:13:47.305Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a4bc287943f5695209ff36bdc89f17b48d68fae7","status":"affected","lessThan":"2da50149981d05955e51c28e982e9ac29bd73417","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"80a15dc4a0214b55ca42675bb0bb2a8d857eb1d0","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"9f0df37520a27ad99eaacf38418b3d2bb5023105","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"6c3c05402547aaca3edb23327b50f01a881831b9","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"34e8f9ec4c9ac235f917747b23a200a5e0ec857b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4proc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.14","versionType":"semver"},{"version":"5.15.154","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.16","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.3","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4proc.c"]}],"references":["https://git.kernel.org/stable/c/2da50149981d05955e51c28e982e9ac29bd73417","https://git.kernel.org/stable/c/80a15dc4a0214b55ca42675bb0bb2a8d857eb1d0","https://git.kernel.org/stable/c/9f0df37520a27ad99eaacf38418b3d2bb5023105","https://git.kernel.org/stable/c/6c3c05402547aaca3edb23327b50f01a881831b9","https://git.kernel.org/stable/c/34e8f9ec4c9ac235f917747b23a200a5e0ec857b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53381.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53381","state":"PUBLISHED","datePublished":"2025-09-18T13:33:26.234Z","dateUpdated":"2026-08-05T09:13:47.305Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-09-17T14:54:09.736Z"},"containers":{"cna":{"title":"NFSD: fix leaked reference count of nfsd4_ssc_umount_item","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix leaked reference count of nfsd4_ssc_umount_item\n\nThe reference count of nfsd4_ssc_umount_item is not decremented\non error conditions. This prevents the laundromat from unmounting\nthe vfsmount of the source file.\n\nThis patch decrements the reference count of nfsd4_ssc_umount_item\non error."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a4bc287943f5695209ff36bdc89f17b48d68fae7","status":"affected","lessThan":"2da50149981d05955e51c28e982e9ac29bd73417","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"80a15dc4a0214b55ca42675bb0bb2a8d857eb1d0","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"9f0df37520a27ad99eaacf38418b3d2bb5023105","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"6c3c05402547aaca3edb23327b50f01a881831b9","versionType":"git"},{"version":"f4e44b393389c77958f7c58bf4415032b4cda15b","status":"affected","lessThan":"34e8f9ec4c9ac235f917747b23a200a5e0ec857b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4proc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.14","versionType":"semver"},{"version":"5.15.154","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.16","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.3","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4proc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2da50149981d05955e51c28e982e9ac29bd73417"},{"url":"https://git.kernel.org/stable/c/80a15dc4a0214b55ca42675bb0bb2a8d857eb1d0"},{"url":"https://git.kernel.org/stable/c/9f0df37520a27ad99eaacf38418b3d2bb5023105"},{"url":"https://git.kernel.org/stable/c/6c3c05402547aaca3edb23327b50f01a881831b9"},{"url":"https://git.kernel.org/stable/c/34e8f9ec4c9ac235f917747b23a200a5e0ec857b"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The flaw is in nfsd's NFSv4.2 OP_COPY handler (nfsd4_copy), reached by sending a COMPOUND over TCP/2049 to the in-kernel NFS server; no local access is required.\nAC:L - The attacker controls the trigger by issuing concurrent async inter-server COPY requests that exhaust kthread/memory resources so setup succeeds then out_err runs, yielding a deterministic per-failure nsui_refcnt leak with no race outside attacker control.\nPR:N - Under AUTH_SYS (default for typical NFS deployments) the server verifies no secret; EXCHANGE_ID/CREATE_SESSION/OPEN succeed for any host allowed by the export, so no server-verified privileges are required.\nUI:N - The attacker's own NFS client issues the COPY compounds directly; no administrator or other user action on the server is required.\nS:U - The leaked nfsd4_ssc_umount_item/vfsmount references remain within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:N - A reference-count leak neither reads out-of-bounds nor exposes kernel memory to the client; COPY replies are unchanged and no freed or uninitialized data is disclosed.\nI:N - No out-of-bounds write or object corruption occurs—the nsui_refcnt merely stays elevated—so there is no write primitive or control-flow hijack.\nA:H - Each failed async inter-COPY permanently pins the source vfsmount (and associated NFS client state) because the laundromat skips entries with refcnt>1, and the leak is repeatable without bound by a remote client until kernel mounts/memory are exhausted."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T09:13:47.305Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"5.15.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.1.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"id":"CVE-2023-53381","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-01-14T18:56:23.125939Z"}}}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-noinfo Not enough information"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-14T19:03:04.270Z"}}]}}}