{"api_version":"1","generated_at":"2026-09-12T06:45:28+00:00","cve":"CVE-2026-89664","urls":{"html":"https://cve.report/CVE-2026-89664","api":"https://cve.report/api/cve/CVE-2026-89664.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89664","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89664"},"summary":{"title":"nfsd: release OPEN-decoded posix ACLs via op_release","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: release OPEN-decoded posix ACLs via op_release\n\nnfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates\nrefcounted struct posix_acl objects via posix_acl_alloc() and stores\nthem in open->op_pacl and open->op_dpacl. These pointers must be\nreleased once the OPEN compound finishes.\n\nWhen nfsd4_decode_open_claim4() returns a non-seqid-mutating error,\nthe dispatcher short-circuits before op_func runs:\n\n    nfsd4_proc_compound()\n      if (op->status && op->opnum == OP_OPEN)\n          op->status = nfsd4_open_omfg(...)\n              if (!seqid_mutating_err(ntohl(op->status)))\n                  return op->status;   /* nfsd4_open() never runs */\n      ...\n      opdesc->op_release(&op->u)  /* must still release op_pacl/op_dpacl */\n\nBefore this change OP_OPEN had no .op_release in nfsd4_ops[], and the\nrelease pair lived inside nfsd4_open() at its out_err: label. On the\nshort-circuit path nfsd4_open() is never invoked, so both posix_acl\nrefs leak on every malformed OPEN compound that carries valid POSIX\nACL createhow4 attributes.\n\nAdd nfsd4_open_release() and wire it as .op_release for OP_OPEN.\nposix_acl_release() is NULL-safe, so the single release site covers\nboth the normal path and the nfsd4_open_omfg short-circuit. Remove\nthe matching posix_acl_release() pair from nfsd4_open()'s out_err:\nlabel to avoid double-releasing.\n\nThe compound loop has two encoding branches: nfsd4_encode_operation()\nfor normal ops, and nfsd4_encode_replay() for v4.0 replayed ops.\nop_release was only called from nfsd4_encode_operation(), so resources\nattached to op->u leak on the replay path.\n\nMove the op_release() call out of nfsd4_encode_operation() and the\nreplay branch, placing it after the if-else in nfsd4_proc_compound().\nThis gives a single call site in a fairly obviously-correct place,\ncovering both the normal encoding and replay paths.","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/5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921","name":"https://git.kernel.org/stable/c/5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8215892993ea9f5231da4fa9eb42428a286fce8b","name":"https://git.kernel.org/stable/c/8215892993ea9f5231da4fa9eb42428a286fce8b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89664","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89664","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5fc51dfc2eb160bd7ab3251ab1767cacf9c8bf05 5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5fc51dfc2eb160bd7ab3251ab1767cacf9c8bf05 8215892993ea9f5231da4fa9eb42428a286fce8b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 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/nfs4proc.c","fs/nfsd/nfs4xdr.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921","status":"affected","version":"5fc51dfc2eb160bd7ab3251ab1767cacf9c8bf05","versionType":"git"},{"lessThan":"8215892993ea9f5231da4fa9eb42428a286fce8b","status":"affected","version":"5fc51dfc2eb160bd7ab3251ab1767cacf9c8bf05","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/nfsd/nfs4proc.c","fs/nfsd/nfs4xdr.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.0"},{"lessThan":"7.0","status":"unaffected","version":"0","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":"7.2.4","versionStartIncluding":"7.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"7.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: release OPEN-decoded posix ACLs via op_release\n\nnfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates\nrefcounted struct posix_acl objects via posix_acl_alloc() and stores\nthem in open->op_pacl and open->op_dpacl. These pointers must be\nreleased once the OPEN compound finishes.\n\nWhen nfsd4_decode_open_claim4() returns a non-seqid-mutating error,\nthe dispatcher short-circuits before op_func runs:\n\n    nfsd4_proc_compound()\n      if (op->status && op->opnum == OP_OPEN)\n          op->status = nfsd4_open_omfg(...)\n              if (!seqid_mutating_err(ntohl(op->status)))\n                  return op->status;   /* nfsd4_open() never runs */\n      ...\n      opdesc->op_release(&op->u)  /* must still release op_pacl/op_dpacl */\n\nBefore this change OP_OPEN had no .op_release in nfsd4_ops[], and the\nrelease pair lived inside nfsd4_open() at its out_err: label. On the\nshort-circuit path nfsd4_open() is never invoked, so both posix_acl\nrefs leak on every malformed OPEN compound that carries valid POSIX\nACL createhow4 attributes.\n\nAdd nfsd4_open_release() and wire it as .op_release for OP_OPEN.\nposix_acl_release() is NULL-safe, so the single release site covers\nboth the normal path and the nfsd4_open_omfg short-circuit. Remove\nthe matching posix_acl_release() pair from nfsd4_open()'s out_err:\nlabel to avoid double-releasing.\n\nThe compound loop has two encoding branches: nfsd4_encode_operation()\nfor normal ops, and nfsd4_encode_replay() for v4.0 replayed ops.\nop_release was only called from nfsd4_encode_operation(), so resources\nattached to op->u leak on the replay path.\n\nMove the op_release() call out of nfsd4_encode_operation() and the\nreplay branch, placing it after the if-else in nfsd4_proc_compound().\nThis gives a single call site in a fairly obviously-correct place,\ncovering both the normal encoding and replay paths."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:45:51.319Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921"},{"url":"https://git.kernel.org/stable/c/8215892993ea9f5231da4fa9eb42428a286fce8b"}],"title":"nfsd: release OPEN-decoded posix ACLs via op_release","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89664","datePublished":"2026-09-11T19:45:51.319Z","dateReserved":"2026-09-11T19:38:34.745Z","dateUpdated":"2026-09-11T19:45:51.319Z","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":"89664","Ordinal":"1","Title":"nfsd: release OPEN-decoded posix ACLs via op_release","CVE":"CVE-2026-89664","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89664","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: release OPEN-decoded posix ACLs via op_release\n\nnfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates\nrefcounted struct posix_acl objects via posix_acl_alloc() and stores\nthem in open->op_pacl and open->op_dpacl. These pointers must be\nreleased once the OPEN compound finishes.\n\nWhen nfsd4_decode_open_claim4() returns a non-seqid-mutating error,\nthe dispatcher short-circuits before op_func runs:\n\n    nfsd4_proc_compound()\n      if (op->status && op->opnum == OP_OPEN)\n          op->status = nfsd4_open_omfg(...)\n              if (!seqid_mutating_err(ntohl(op->status)))\n                  return op->status;   /* nfsd4_open() never runs */\n      ...\n      opdesc->op_release(&op->u)  /* must still release op_pacl/op_dpacl */\n\nBefore this change OP_OPEN had no .op_release in nfsd4_ops[], and the\nrelease pair lived inside nfsd4_open() at its out_err: label. On the\nshort-circuit path nfsd4_open() is never invoked, so both posix_acl\nrefs leak on every malformed OPEN compound that carries valid POSIX\nACL createhow4 attributes.\n\nAdd nfsd4_open_release() and wire it as .op_release for OP_OPEN.\nposix_acl_release() is NULL-safe, so the single release site covers\nboth the normal path and the nfsd4_open_omfg short-circuit. Remove\nthe matching posix_acl_release() pair from nfsd4_open()'s out_err:\nlabel to avoid double-releasing.\n\nThe compound loop has two encoding branches: nfsd4_encode_operation()\nfor normal ops, and nfsd4_encode_replay() for v4.0 replayed ops.\nop_release was only called from nfsd4_encode_operation(), so resources\nattached to op->u leak on the replay path.\n\nMove the op_release() call out of nfsd4_encode_operation() and the\nreplay branch, placing it after the if-else in nfsd4_proc_compound().\nThis gives a single call site in a fairly obviously-correct place,\ncovering both the normal encoding and replay paths.","Type":"Description","Title":"nfsd: release OPEN-decoded posix ACLs via op_release"}]}}}