{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99040","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.387Z","datePublished":"2026-10-23T12:21:59.288Z","dateUpdated":"2026-10-30T12:41:13.694Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-30T12:41:13.694Z"},"descriptions":[{"lang":"en","value":"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["security/keys/key.c"],"versions":[{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"24806fc9bca28fa1433bf938d1424dcb45d80e50","status":"affected","versionType":"git"},{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"9a5c2700336878465a630804a2d21864f22eca9c","status":"affected","versionType":"git"},{"version":"5ac7eace2d00eab5ae0e9fdee63e38aee6001f7c","lessThan":"b3e404550dc2b7f3d4bb64b1da8005a1fa9a798d","status":"affected","versionType":"git"},{"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"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["security/keys/key.c"],"versions":[{"version":"4.7","status":"affected"},{"version":"0","lessThan":"4.7","status":"unaffected","versionType":"semver"},{"version":"5.10.273","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.224","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","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"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.2.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.3"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/24806fc9bca28fa1433bf938d1424dcb45d80e50"},{"url":"https://git.kernel.org/stable/c/9a5c2700336878465a630804a2d21864f22eca9c"},{"url":"https://git.kernel.org/stable/c/b3e404550dc2b7f3d4bb64b1da8005a1fa9a798d"},{"url":"https://git.kernel.org/stable/c/305f1828b871dd46bf41addeb6f11d2c162dcb25"},{"url":"https://git.kernel.org/stable/c/f99399b48e3edd6851fac34cd329bab9f1f33baf"},{"url":"https://git.kernel.org/stable/c/11516a0c402a6c1fa52254aa70d8d65fb921e59e"},{"url":"https://git.kernel.org/stable/c/da0b595d8e6e2dd798f6e34e09dc51a13b888514"},{"url":"https://git.kernel.org/stable/c/dd3ea3fcba7c75493760cdbccd35f029597e8d5e"}],"title":"KEYS: Fix add_key() race with keyring restriction","x_generator":{"engine":"bippy-1.2.0"}}}}