CVE-2024-56549

{"id": "CVE-2024-56549", "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": "2024-12-27T14:15:34.747", "references": [{"url": "https://git.kernel.org/stable/c/31ad74b20227ce6b40910ff78b1c604e42975cf1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/785408bbafcfa24c9fc5b251f03fd0780ce182bd", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9582c7664103c9043e80a78f5c382aa6bdd67418", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d6bba3ece960129a553d4b16f1b00c884dc0993a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f98770440c9bc468e2fd878212ec9526dbe08293", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html", "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: Fix NULL pointer dereference in object->file\n\nAt present, the object->file has the NULL pointer dereference problem in\nondemand-mode. The root cause is that the allocated fd and object->file\nlifetime are inconsistent, and the user-space invocation to anon_fd uses\nobject->file. Following is the process that triggers the issue:\n\n\t [write fd]\t\t\t\t[umount]\ncachefiles_ondemand_fd_write_iter\n\t\t\t\t fscache_cookie_state_machine\n\t\t\t\t\t cachefiles_withdraw_cookie\n if (!file) return -ENOBUFS\n\t\t\t\t\t cachefiles_clean_up_object\n\t\t\t\t\t cachefiles_unmark_inode_in_use\n\t\t\t\t\t fput(object->file)\n\t\t\t\t\t object->file = NULL\n // file NULL pointer dereference!\n __cachefiles_write(..., file, ...)\n\nFix this issue by add an additional reference count to the object->file\nbefore write/llseek, and decrement after it finished."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: cachefiles: Arreglar la desreferencia de puntero NULL en object->file En la actualidad, object->file tiene el problema de desreferencia de puntero NULL en el modo ondemand. La causa ra\u00edz es que el fd asignado y el tiempo de vida de object->file son inconsistentes, y la invocaci\u00f3n del espacio de usuario a anon_fd usa object->file. A continuaci\u00f3n, se muestra el proceso que desencadena el problema: [write fd] [umount] cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file \u00a1Desreferencia de puntero NULL! __cachefiles_write(..., file, ...) Solucione este problema agregando un recuento de referencia adicional al objeto->archivo antes de escribir/llseek, y disminuya despu\u00e9s de que finalice."}], "lastModified": "2025-11-03T20:16:53.607", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A482F6D5-4DB0-4611-AF23-1D568CE9F2BF", "versionEndExcluding": "6.11.11", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D8882B1B-2ABC-4838-AC1D-DBDBB5764776", "versionEndExcluding": "6.12.2", "versionStartIncluding": "6.12"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}