{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89669", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.746Z", "datePublished": "2026-09-11T19:45:55.111Z", "dateUpdated": "2026-10-19T08:50:42.637Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:50:42.637Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: initialize copy-notify stateid before publishing it\n\nnfsd4_copy_notify() finished initializing the cpntf state after\nnfs4_alloc_init_cpntf_state() had already linked it into the\ns2s_cp_stateids IDR and the parent's sc_cp_list, with cs_count == 1 (the\nmembership reference) and none held for the caller. A racing\nOFFLOAD_CANCEL (crafted cl_id == nn->s2s_cp_cl_id plus the guessable\nso_id) could reach manage_cpntf_state() and free the entry, turning the\ncaller's subsequent cpn_cnr_stateid read and cp_p_stateid/cp_p_clid\nwrites into use-after-free. The owning clientid was also only recorded\nafter publication, so it could not gate an ownership check in that window.\n\nRecord cp_p_stateid and cp_p_clid inside nfs4_alloc_init_cpntf_state()\nbefore nfs4_init_cp_state() publishes the entry, and return it with an\nextra reference. The caller reads the stateid under that reference and\ndrops it with nfs4_put_cpntf_state(); on a late error the laundromat\nreaps the entry." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The UAF is in nfsd COPY_NOTIFY (nfsd4_copy_notify/nfs4_alloc_init_cpntf_state). NFSv4.2 COPY_NOTIFY and a racing OFFLOAD_CANCEL are processed from compounds over TCP/2049 via nfsd4_proc_compound, so a remote NFS client reaches the published cpntf object over the network.\nAC:L - The attacker controls both sides: one compound publishes the cpntf IDR entry via COPY_NOTIFY while a concurrent OFFLOAD_CANCEL uses the leaked nn->s2s_cp_cl_id and a cyclic guessable so_id to kfree it before initialization finishes; the race is retryable on multiple session slots with no condition outside attacker control.\nPR:N - Default AUTH_SYS/AUTH_NULL nfsd exports do no cryptographic authentication; any host allowed by the export ACL can EXCHANGE_ID/CREATE_SESSION, OPEN a readable file, and issue COPY_NOTIFY and OFFLOAD_CANCEL. No local account or capability on the NFS server is required.\nUI:N - The attacking NFS client drives COPY_NOTIFY and the concurrent OFFLOAD_CANCEL on its own connections; no victim user or administrator action on the NFS server is required at attack time.\nS:U - The use-after-free corrupts a kmalloc'd nfs4_cpntf_state in the host kernel's nfsd copy-notify tables. Impact stays in that kernel security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - After OFFLOAD_CANCEL kfree's the object (cs_count was 1), nfsd4_copy_notify memcpy's the freed cp_stateid.cs_stid into the RPC reply; reclaim of that kmalloc slab lets the attacker disclose kernel memory. Per kernel guidance a use-after-free is C:H.\nI:H - The same path then writes cp_p_stateid and cp_p_clid into the freed nfs4_cpntf_state, a use-after-free write primitive usable for heap corruption and control-flow hijacking. Per kernel guidance a use-after-free is I:H.\nA:H - Use-after-free of nfs4_cpntf_state in an nfsd worker oopses or panics the NFS server even without full exploitation, and the attacker can repeat the concurrent RPC sequence to deny service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs4proc.c", "fs/nfsd/nfs4state.c" ], "versions": [ { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "863b6e995665472f2af5be2436a874ab6a9e5ac6", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "d18d36395d973ef7372c8e6724970585f75b5c0b", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "4415a692346a39fdb647cbd717eda510159aaf55", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "9caad13b7cfe9ccb90cc405ac77335800e086595", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "e08a3dcaca0505f861e344a387f37f94d95dbdc2", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "a4d7fedcaaf33e60a01e53eafca9041ef966212f", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "4cdef96892f4fa6e70c405b6e8f2fd6972f3b64b", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "129643893b79f8a3c6b72045f933fbab5ee424ca", "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/nfs4proc.c", "fs/nfsd/nfs4state.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "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": "5.6", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/863b6e995665472f2af5be2436a874ab6a9e5ac6" }, { "url": "https://git.kernel.org/stable/c/d18d36395d973ef7372c8e6724970585f75b5c0b" }, { "url": "https://git.kernel.org/stable/c/4415a692346a39fdb647cbd717eda510159aaf55" }, { "url": "https://git.kernel.org/stable/c/9caad13b7cfe9ccb90cc405ac77335800e086595" }, { "url": "https://git.kernel.org/stable/c/e08a3dcaca0505f861e344a387f37f94d95dbdc2" }, { "url": "https://git.kernel.org/stable/c/a4d7fedcaaf33e60a01e53eafca9041ef966212f" }, { "url": "https://git.kernel.org/stable/c/4cdef96892f4fa6e70c405b6e8f2fd6972f3b64b" }, { "url": "https://git.kernel.org/stable/c/129643893b79f8a3c6b72045f933fbab5ee424ca" } ], "title": "nfsd: initialize copy-notify stateid before publishing it", "x_generator": { "engine": "bippy-1.2.0" } } } }