{"id":"CVE-2026-93212","revision":"798cd590c4c34a8e86c9fa24bf28780a","records":[{"revision":"798cd590c4c34a8e86c9fa24bf28780a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-93212","aliases":[],"title":"nfsd: guard nfsd_serv deref in nfsd_file_net_dispose","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: guard nfsd_serv deref in nfsd_file_net_dispose\n\nnfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd\nservice thread loop calls it to drain entries that the filecache\ngarbage collector and shrinker append via\nnfsd_file_dispose_list_delayed().  During per-net teardown,\nnn->nfsd_serv is cleared before the filecache laundrette is shut\ndown, so the service thread can still run a dispose pass that finds\nmore than eight entries on l->freeme and dereferences a NULL\nsvc_serv:\n\n    nfsd service thread loop\n      nfsd_file_net_dispose(nn)\n        if (!list_empty(&l->freeme)) {\n            ...\n            svc_wake_up(nn->nfsd_serv);   /* nn->nfsd_serv == NULL */\n        }\n\nThe sibling helper nfsd_file_dispose_list_delayed() already documents\nthis ordering and caches nn->nfsd_serv into a local before testing it\nfor NULL.  nfsd_file_net_dispose() was introduced with the same raw\nsvc_wake_up(nn->nfsd_serv) call and never picked up the guard.\n\nFix by loading nn->nfsd_serv into a local svc_serv pointer and only\ncalling svc_wake_up() when it is non-NULL, matching the pattern in\nnfsd_file_dispose_list_delayed().","state":0,"publishedAt":"2026-09-24T15:10:35.28+00:00","modifiedAt":"2026-10-19T09:07:24.291+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/filecache.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"f4776c1c4b38fbc459420321c8ece87d0f7f95fb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"59baf45a06435194005fc5fa9a42d89f77a30432\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"766170b4fd2daaf5c4d6735560101474e18edab6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffb402596147ac583f3464ff5c48feb9423e3838\",\n                            \"lessThan\": \"9f1ddfc8cb9076592401a611eb3a44d36186d014\",\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/filecache.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.9\",\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":[],"references":["https://git.kernel.org/stable/c/f4776c1c4b38fbc459420321c8ece87d0f7f95fb","https://git.kernel.org/stable/c/59baf45a06435194005fc5fa9a42d89f77a30432","https://git.kernel.org/stable/c/766170b4fd2daaf5c4d6735560101474e18edab6","https://git.kernel.org/stable/c/9f1ddfc8cb9076592401a611eb3a44d36186d014"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-93212","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-93212","identifiers":["CVE-2026-93212"]},"retained":false,"historicalAffected":[]}],"coverage":[]}