{"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":"2026-09-14T12:01:55.666Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T12:01:55.666Z"},"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-rc1","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-rc1"}]}]}],"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"}}}}