{"id":"CVE-2025-21655","revision":null,"records":[{"revision":"737a6d00e3504eb5bce96c47e3efa39a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2025-21655","aliases":[],"title":"io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/eventfd: ensure io_eventfd_signal() defers another RCU period\n\nio_eventfd_do_signal() is invoked from an RCU callback, but when\ndropping the reference to the io_ev_fd, it calls io_eventfd_free()\ndirectly if the refcount drops to zero. This isn't correct, as any\npotential freeing of the io_ev_fd should be deferred another RCU grace\nperiod.\n\nJust call io_eventfd_put() rather than open-code the dec-and-test and\nfree, which will correctly defer it another RCU grace period.","state":0,"publishedAt":"2025-01-20T13:48:40.544+00:00","modifiedAt":"2026-10-15T01:02:51.468+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                        \"io_uring/eventfd.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"6b63308c28987c6010b1180c72a6db4df6c68033\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"c9a40292a44e78f71258b8522655bffaf5753bdb\",\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                        \"io_uring/eventfd.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.125\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.72\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.10\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.13\",\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:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/6b63308c28987c6010b1180c72a6db4df6c68033","https://git.kernel.org/stable/c/8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10","https://git.kernel.org/stable/c/a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7","https://git.kernel.org/stable/c/c9a40292a44e78f71258b8522655bffaf5753bdb","https://project-zero.issues.chromium.org/issues/388499293"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-21655","license":"CVE Program Terms of Use","key":"cve-program:CVE-2025-21655","identifiers":["CVE-2025-21655"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-07fb27e56bcd48c9b51e00bd5fd6fa23","complete":false,"records":13655,"lastAttemptAt":"2026-11-09T20:09:02.2862652+00:00","lastSuccessAt":"2026-11-09T20:09:02.3526702+00:00","error":null,"lastVerifiedAt":"2026-11-09T20:09:02.3526702+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T20:04:25.0077254+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T20:04:25.0077254+00:00","lastSuccessAt":"2026-11-09T20:04:25.193761+00:00","error":null,"lastVerifiedAt":"2026-11-09T20:04:25.1937612+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. 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