{"schema":"threatline.record/2","record":{"id":"CVE-2026-99040","aliases":[],"summary":"KEYS: Fix add_key() race with keyring restriction","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nKEYS: Fix add_key() race with keyring restriction\n\n__key_create_or_update() snapshots keyring->restrict_link before taking\nthe destination keyring's semaphore.  keyring_restrict() installs a\nrestriction while holding that semaphore.\n\nThis allows a writer to observe no restriction, wait for the keyring\nowner to install a reject-all restriction and return successfully, and\nthen link a key using the stale NULL snapshot.  The writer only needs\nwrite permission on the destination keyring.\n\nMove the restrict_link read after __key_link_lock() and\n__key_link_begin().  The read and the subsequent restriction check are\nthen serialized with restriction installation by keyring->sem.\n\nThe race was reproduced on v7.2.8 in 19 executions where restriction\ninstallation returned before the link completed.  All 19 linked the key\ndespite the reject-all restriction.  With this change, 312 executions\nreached the same ordering and every add_key() call failed with -EPERM.\n\nThe issue was found by manual concurrency analysis assisted by AI-based\nanalysis and independently verified with a QEMU reproducer and kernel\ninstrumentation.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99040","source_modified_at":"2026-10-23T12:21:59.288Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"Linux","vendor":"Linux","versions":[{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"305f1828b871dd46bf41addeb6f11d2c162dcb25","status":"affected","versionType":"git"},{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"f99399b48e3edd6851fac34cd329bab9f1f33baf","status":"affected","versionType":"git"},{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"11516a0c402a6c1fa52254aa70d8d65fb921e59e","status":"affected","versionType":"git"},{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"da0b595d8e6e2dd798f6e34e09dc51a13b888514","status":"affected","versionType":"git"},{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"dd3ea3fcba7c75493760cdbccd35f029597e8d5e","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99040","source_modified_at":"2026-10-23T12:21:59.288Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"Linux","vendor":"Linux","versions":[{"version":"4.7","status":"affected"},{"version":"0","lessThan":"4.7","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.113","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.57","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.11","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99040","source_modified_at":"2026-10-23T12:21:59.288Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Linux","ecosystem":null},"version":"305f1828b871dd46bf41addeb6f11d2c162dcb25","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99040","source_modified_at":"2026-10-23T12:21:59.288Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Linux","ecosystem":null},"version":"11516a0c402a6c1fa52254aa70d8d65fb921e59e","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-23T12:21:59.288Z","modified_at":"2026-10-23T12:21:59.288Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-99040","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T12:21:59.288Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/305f1828b871dd46bf41addeb6f11d2c162dcb25"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f99399b48e3edd6851fac34cd329bab9f1f33baf"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/11516a0c402a6c1fa52254aa70d8d65fb921e59e"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/da0b595d8e6e2dd798f6e34e09dc51a13b888514"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/dd3ea3fcba7c75493760cdbccd35f029597e8d5e"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-23T12:21:59.288Z","content_hash":"8f8ee9222b032ecde4626a09419e6d90d565cac34fecc4896a9c6decc19314fd"}}