CVE-2021-47527

{"id": "CVE-2021-47527", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2024-05-24T15:15:15.580", "references": [{"url": "https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-401"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nserial: core: fix transmit-buffer reset and memleak\n\nCommit 761ed4a94582 (\"tty: serial_core: convert uart_close to use\ntty_port_close\") converted serial core to use tty_port_close() but\nfailed to notice that the transmit buffer still needs to be freed on\nfinal close.\n\nNot freeing the transmit buffer means that the buffer is no longer\ncleared on next open so that any ioctl() waiting for the buffer to drain\nmight wait indefinitely (e.g. on termios changes) or that stale data can\nend up being transmitted in case tx is restarted.\n\nFurthermore, the buffer of any port that has been opened would leak on\ndriver unbind.\n\nNote that the port lock is held when clearing the buffer pointer due to\nthe ldisc race worked around by commit a5ba1d95e46e (\"uart: fix race\nbetween uart_put_char() and uart_shutdown()\").\n\nAlso note that the tty-port shutdown() callback is not called for\nconsole ports so it is not strictly necessary to free the buffer page\nafter releasing the lock (cf. d72402145ace (\"tty/serial: do not free\ntrasnmit buffer page under port lock\"))."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: serial: core: fix transmit-buffer reset y memleak commit 761ed4a94582 (\"tty: serial_core: convert uart_close to use tty_port_close\") n\u00facleo serial convertido para usar tty_port_close() pero no se dio cuenta que el b\u00fafer de transmisi\u00f3n todav\u00eda necesita ser liberado en el cierre final. No liberar el b\u00fafer de transmisi\u00f3n significa que el b\u00fafer ya no se borra en la pr\u00f3xima apertura, por lo que cualquier ioctl() que espere a que se drene el b\u00fafer podr\u00eda esperar indefinidamente (por ejemplo, en cambios de termios) o que los datos obsoletos pueden terminar transmiti\u00e9ndose en caso de que tx sea reiniciado. Adem\u00e1s, el b\u00fafer de cualquier puerto que se haya abierto se filtrar\u00eda al desvincular el controlador. Tenga en cuenta que el bloqueo del puerto se mantiene al borrar el puntero del b\u00fafer debido a la ejecuci\u00f3n de ldisc solucionada mediante el commit a5ba1d95e46e (\"uart: corrige la ejecuci\u00f3n entre uart_put_char() y uart_shutdown()\"). Tambi\u00e9n tenga en cuenta que la devoluci\u00f3n de llamada tty-portshutdown() no se llama para los puertos de consola, por lo que no es estrictamente necesario liberar la p\u00e1gina del b\u00fafer despu\u00e9s de liberar el bloqueo (cf. d72402145ace (\"tty/serial: no liberar la p\u00e1gina del b\u00fafer de transmisi\u00f3n en el puerto cerrar con llave\"))."}], "lastModified": "2025-09-24T19:47:00.073", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "27AF42F1-1044-4E2C-B512-7223CC4AC025", "versionEndExcluding": "4.9.292", "versionStartIncluding": "4.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7080D941-9847-42F5-BA50-0A03CFB61FD1", "versionEndExcluding": "4.14.257", "versionStartIncluding": "4.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FFE5D9F3-CF1C-4DE8-9116-2EBE7BDEF7FD", "versionEndExcluding": "4.19.220", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D2D8DC10-1823-4334-BD0F-C1B620602FF9", "versionEndExcluding": "5.4.164", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AE5B4333-2C46-40C3-8B42-0168AD91DDE1", "versionEndExcluding": "5.10.84", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A696A60B-2782-4119-83DD-1EFFBC903F02", "versionEndExcluding": "5.15.7", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "357AA433-37E8-4323-BFB2-3038D6E4B414"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A73429BA-C2D9-4D0C-A75F-06A1CA8B3983"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F621B5E3-E99D-49E7-90B9-EC3B77C95383"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}