{"id":"CVE-2026-89664","revision":"48b504fe0baa49c29bceb1a546922c1d","records":[{"revision":"48b504fe0baa49c29bceb1a546922c1d","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89664","aliases":[],"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":0,"publishedAt":"2026-09-11T19:45:51.319+00:00","modifiedAt":"2026-10-19T08:50:35.77+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfsd/nfs4proc.c\",\n                        \"fs/nfsd/nfs4xdr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5fc51dfc2eb160bd7ab3251ab1767cacf9c8bf05\",\n                            \"lessThan\": \"5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5fc51dfc2eb160bd7ab3251ab1767cacf9c8bf05\",\n                            \"lessThan\": \"8215892993ea9f5231da4fa9eb42428a286fce8b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfsd/nfs4proc.c\",\n                        \"fs/nfsd/nfs4xdr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"7.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921","https://git.kernel.org/stable/c/8215892993ea9f5231da4fa9eb42428a286fce8b"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89664","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89664","identifiers":["CVE-2026-89664"]},"retained":false,"historicalAffected":[]}],"coverage":[]}