{"api_version":"1","generated_at":"2026-09-12T11:58:29+00:00","cve":"CVE-2026-89660","urls":{"html":"https://cve.report/CVE-2026-89660","api":"https://cve.report/api/cve/CVE-2026-89660.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89660","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89660"},"summary":{"title":"NFSD: Prevent client use-after-free during admin state revocation","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it.  The client survives only because\n__destroy_client() drains its stateids before free_client() runs.\n\nnfsd4_revoke_states() drops nn->client_lock across revoke_one_stid(),\nwhich dereferences the client to revoke a stateid and read\nclp->cl_minorversion.  A teardown racing the dropped lock can free\nthe client first.\n\nPinning cl_rpc_users under client_lock blocks the DESTROY_CLIENTID and\nEXCHANGE_ID teardown, which refuses while cl_rpc_users is non-zero.\nforce_expire_client() ignores it: once its wait for cl_rpc_users to\nreach zero has passed, a later pin goes unnoticed.\n\nUnder client_lock, skip a client whose cl_time is already zero --\nforce_expire_client() clears it there before waiting -- otherwise pin\ncl_rpc_users before dropping the lock.  The walk then either sees the\nexpiry and skips, or pins in time for that wait to cover the revoke.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:52","updated_at":"2026-09-11 20:19:52"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/bf1f948691523282cc4905bc6cd325e0c0b49e6a","name":"https://git.kernel.org/stable/c/bf1f948691523282cc4905bc6cd325e0c0b49e6a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e270e5a0778e5bff852c8862ce9576ce70359393","name":"https://git.kernel.org/stable/c/e270e5a0778e5bff852c8862ce9576ce70359393","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/549bd9868e9d77b07ea94870940d64342829c6ad","name":"https://git.kernel.org/stable/c/549bd9868e9d77b07ea94870940d64342829c6ad","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89660","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89660","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc 549bd9868e9d77b07ea94870940d64342829c6ad git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc bf1f948691523282cc4905bc6cd325e0c0b49e6a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc e270e5a0778e5bff852c8862ce9576ce70359393 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/nfsd/nfs4state.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"549bd9868e9d77b07ea94870940d64342829c6ad","status":"affected","version":"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc","versionType":"git"},{"lessThan":"bf1f948691523282cc4905bc6cd325e0c0b49e6a","status":"affected","version":"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc","versionType":"git"},{"lessThan":"e270e5a0778e5bff852c8862ce9576ce70359393","status":"affected","version":"1c13bf9f2e3cd5a59ef988c6c5a49fe0f02bcdfc","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/nfsd/nfs4state.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.9"},{"lessThan":"6.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it.  The client survives only because\n__destroy_client() drains its stateids before free_client() runs.\n\nnfsd4_revoke_states() drops nn->client_lock across revoke_one_stid(),\nwhich dereferences the client to revoke a stateid and read\nclp->cl_minorversion.  A teardown racing the dropped lock can free\nthe client first.\n\nPinning cl_rpc_users under client_lock blocks the DESTROY_CLIENTID and\nEXCHANGE_ID teardown, which refuses while cl_rpc_users is non-zero.\nforce_expire_client() ignores it: once its wait for cl_rpc_users to\nreach zero has passed, a later pin goes unnoticed.\n\nUnder client_lock, skip a client whose cl_time is already zero --\nforce_expire_client() clears it there before waiting -- otherwise pin\ncl_rpc_users before dropping the lock.  The walk then either sees the\nexpiry and skips, or pins in time for that wait to cover the revoke."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:45:48.341Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/549bd9868e9d77b07ea94870940d64342829c6ad"},{"url":"https://git.kernel.org/stable/c/bf1f948691523282cc4905bc6cd325e0c0b49e6a"},{"url":"https://git.kernel.org/stable/c/e270e5a0778e5bff852c8862ce9576ce70359393"}],"title":"NFSD: Prevent client use-after-free during admin state revocation","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89660","datePublished":"2026-09-11T19:45:48.341Z","dateReserved":"2026-09-11T19:38:34.744Z","dateUpdated":"2026-09-11T19:45:48.341Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:52","lastModifiedDate":"2026-09-11 20:19:52","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89660","Ordinal":"1","Title":"NFSD: Prevent client use-after-free during admin state revocatio","CVE":"CVE-2026-89660","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89660","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during admin state revocation\n\nA stateid holds only a bare pointer to its nfs4_client; a stateid\nreference does not pin it.  The client survives only because\n__destroy_client() drains its stateids before free_client() runs.\n\nnfsd4_revoke_states() drops nn->client_lock across revoke_one_stid(),\nwhich dereferences the client to revoke a stateid and read\nclp->cl_minorversion.  A teardown racing the dropped lock can free\nthe client first.\n\nPinning cl_rpc_users under client_lock blocks the DESTROY_CLIENTID and\nEXCHANGE_ID teardown, which refuses while cl_rpc_users is non-zero.\nforce_expire_client() ignores it: once its wait for cl_rpc_users to\nreach zero has passed, a later pin goes unnoticed.\n\nUnder client_lock, skip a client whose cl_time is already zero --\nforce_expire_client() clears it there before waiting -- otherwise pin\ncl_rpc_users before dropping the lock.  The walk then either sees the\nexpiry and skips, or pins in time for that wait to cover the revoke.","Type":"Description","Title":"NFSD: Prevent client use-after-free during admin state revocatio"}]}}}