CVE-2026-23286

{"id": "CVE-2026-23286", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "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": "2026-03-25T11:16:23.393", "references": [{"url": "https://git.kernel.org/stable/c/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/2d9f57ea29a1f1772373b98a509b44d49fda609e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/30c9744a989feb22cfbb84170eb0e038a7a2c1da", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5f1cfea7921f5c126a441d973690eeba52677b64", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/622062f24644b4536d3f437e0cf7a8c4bb421665", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7ea92ab075d809ec8a96669a5ecf00f752057875", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e9665986eb127290ceb535bd5d04d7a84265d94f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\natm: lec: fix null-ptr-deref in lec_arp_clear_vccs\n\nsyzkaller reported a null-ptr-deref in lec_arp_clear_vccs().\nThis issue can be easily reproduced using the syzkaller reproducer.\n\nIn the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by\nmultiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc).\nWhen the underlying VCC is closed, lec_vcc_close() iterates over all\nARP entries and calls lec_arp_clear_vccs() for each matched entry.\n\nFor example, when lec_vcc_close() iterates through the hlists in\npriv->lec_arp_empty_ones or other ARP tables:\n\n1. In the first iteration, for the first matched ARP entry sharing the VCC,\nlec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back)\nand sets vcc->user_back to NULL.\n2. In the second iteration, for the next matched ARP entry sharing the same\nVCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from\nvcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it\nvia `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash.\n\nFix this by adding a null check for vpriv before dereferencing\nit. If vpriv is already NULL, it means the VCC has been cleared\nby a previous call, so we can safely skip the cleanup and just\nclear the entry's vcc/recv_vcc pointers.\n\nThe entire cleanup block (including vcc_release_async()) is placed inside\nthe vpriv guard because a NULL vpriv indicates the VCC has already been\nfully released by a prior iteration \u2014 repeating the teardown would\nredundantly set flags and trigger callbacks on an already-closing socket.\n\nThe Fixes tag points to the initial commit because the entry->vcc path has\nbeen vulnerable since the original code. The entry->recv_vcc path was later\nadded by commit 8d9f73c0ad2f (\"atm: fix a memory leak of vcc->user_back\")\nwith the same pattern, and both paths are fixed here."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\natm: lec: corrige desreferencia de puntero nulo en lec_arp_clear_vccs\n\nsyzkaller report\u00f3 una desreferencia de puntero nulo en lec_arp_clear_vccs().\nEste problema puede ser f\u00e1cilmente reproducido usando el reproductor de syzkaller.\n\nEn el m\u00f3dulo ATM LANE (Emulaci\u00f3n de LAN), el mismo atm_vcc puede ser compartido por m\u00faltiples entradas de lec_arp_table (por ejemplo, a trav\u00e9s de entry->vcc o entry->recv_vcc).\nCuando el VCC subyacente se cierra, lec_vcc_close() itera sobre todas las entradas ARP y llama a lec_arp_clear_vccs() para cada entrada coincidente.\n\nPor ejemplo, cuando lec_vcc_close() itera a trav\u00e9s de las hlists en priv->lec_arp_empty_ones u otras tablas ARP:\n\n1. En la primera iteraci\u00f3n, para la primera entrada ARP coincidente que comparte el VCC, lec_arp_clear_vccs() libera el vpriv asociado (que es vcc->user_back) y establece vcc->user_back en NULL.\n2. En la segunda iteraci\u00f3n, para la siguiente entrada ARP coincidente que comparte el mismo VCC, lec_arp_clear_vccs() es llamada de nuevo. Obtiene un vpriv NULL de vcc->user_back (a trav\u00e9s de LEC_VCC_PRIV(vcc)) y luego intenta desreferenciarlo a trav\u00e9s de 'vcc->pop = vpriv->old_pop', lo que lleva a un fallo por desreferencia de puntero nulo.\n\nSoluciona esto a\u00f1adiendo una comprobaci\u00f3n de nulos para vpriv antes de desreferenciarlo. Si vpriv ya es NULL, significa que el VCC ha sido limpiado por una llamada anterior, por lo que podemos omitir de forma segura la limpieza y simplemente limpiar los punteros vcc/recv_vcc de la entrada.\n\nEl bloque de limpieza completo (incluyendo vcc_release_async()) se coloca dentro de la guarda de vpriv porque un vpriv NULL indica que el VCC ya ha sido completamente liberado por una iteraci\u00f3n anterior \u2014 repetir el desmontaje establecer\u00eda banderas de forma redundante y activar\u00eda retrollamadas en un socket que ya se est\u00e1 cerrando.\n\nLa etiqueta Fixes apunta al commit inicial porque la ruta entry->vcc ha sido vulnerable desde el c\u00f3digo original. La ruta entry->recv_vcc fue a\u00f1adida posteriormente por el commit 8d9f73c0ad2f ('atm: fix a memory leak of vcc->user_back') con el mismo patr\u00f3n, y ambas rutas se corrigen aqu\u00ed."}], "lastModified": "2026-05-29T16:33:45.610", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5F0E43E1-33E5-4828-9B4A-F710AF2E7217", "versionEndExcluding": "5.10.253", "versionStartIncluding": "2.6.12.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045", "versionEndExcluding": "5.15.203", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43", "versionEndExcluding": "6.1.167", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267", "versionEndExcluding": "6.6.130", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B3D12E00-E42D-4056-B354-BAD4903C03A5", "versionEndExcluding": "6.12.77", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A5E006E4-59C7-43C1-9231-62A72219F2BA", "versionEndExcluding": "6.18.17", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "69245D10-0B71-485E-80C3-A64F077004D3", "versionEndExcluding": "6.19.7", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6F62EECE-8FB1-4D57-85D8-CB9E23CF313C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4F76C298-81DC-43E4-8FC9-DC005A2116EF"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0AB349B2-3F78-4197-882B-90ADB3BF645A"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6AC88830-A9BC-4607-B572-A4B502FC9FD0"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "476CB3A5-D022-4F13-AAEF-CB6A5785516A"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}