{"id":"CVE-2026-89691","revision":"d1afdc4c1008484eb4851a0c21294292","records":[{"revision":"d1afdc4c1008484eb4851a0c21294292","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89691","aliases":[],"title":"nfsd: clear opcnt on compound arg release to prevent OOB read","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: clear opcnt on compound arg release to prevent OOB read\n\nnfsd4_release_compoundargs() resets args->ops to the inline iops[8]\narray when the dynamically-allocated ops buffer is freed, but leaves\nargs->opcnt at its original value (which can be up to 200 for NFSv4.1+\ncompounds).\n\nIf rq_status_counter is stuck at an odd value (which can happen when\nnfsd_dispatch() hits an error path after setting it odd), the RPC\nstatus dumpit handler reads min(opcnt, 16) entries from args->ops[].\nSince iops only has 8 elements and is the last field in struct\nnfsd4_compoundargs, reading indices 8-15 accesses adjacent slab memory\nand leaks it to userspace via netlink.\n\nZero opcnt unconditionally in nfsd4_release_compoundargs() so stale\ncompound metadata is never exposed through the status interface.\n\n[ cel: Remove the kvfree_rcu_mightsleep() sleep from the exposure window ]","state":0,"publishedAt":"2026-09-11T19:46:11.284+00:00","modifiedAt":"2026-10-19T08:51:04.497+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/nfs4xdr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"58bcdfb2b2e412088839ae740b1a95154dc0b8d0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"e879148867bd4c4cac42e063ffaffa187dddc6fe\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"c1a4f7b1848f95302df598217e1c7a1410c2d0c5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a\",\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/nfs4xdr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.7\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.7\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.109\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\n                            \"lessThanOrEqual\": \"6.18.*\",\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:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/58bcdfb2b2e412088839ae740b1a95154dc0b8d0","https://git.kernel.org/stable/c/e879148867bd4c4cac42e063ffaffa187dddc6fe","https://git.kernel.org/stable/c/c1a4f7b1848f95302df598217e1c7a1410c2d0c5","https://git.kernel.org/stable/c/ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89691","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89691","identifiers":["CVE-2026-89691"]},"retained":false,"historicalAffected":[]}],"coverage":[]}