CVE-2024-35944

{"id": "CVE-2024-35944", "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": "2024-05-19T11:15:50.017", "references": [{"url": "https://git.kernel.org/stable/c/130b0cd064874e0d0f58e18fb00e6f3993e90c74", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/19b070fefd0d024af3daa7329cbc0d00de5302ec", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/491a1eb07c2bd8841d63cb5263455e185be5866f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ad78c5047dc4076d0b3c4fad4f42ffe9c86e8100", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dae70a57565686f16089737adb8ac64471570f73", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e87bb99d2df6512d8ee37a5d63d2ca9a39a8c051", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f15eca95138b3d4ec17b63c3c1937b0aa0d3624b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/feacd430b42bbfa9ab3ed9e4f38b86c43e348c75", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/130b0cd064874e0d0f58e18fb00e6f3993e90c74", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/19b070fefd0d024af3daa7329cbc0d00de5302ec", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/491a1eb07c2bd8841d63cb5263455e185be5866f", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/ad78c5047dc4076d0b3c4fad4f42ffe9c86e8100", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/dae70a57565686f16089737adb8ac64471570f73", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/e87bb99d2df6512d8ee37a5d63d2ca9a39a8c051", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/f15eca95138b3d4ec17b63c3c1937b0aa0d3624b", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/feacd430b42bbfa9ab3ed9e4f38b86c43e348c75", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html", "tags": ["Third Party Advisory", "Mailing List"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html", "tags": ["Third Party Advisory", "Mailing List"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nVMCI: Fix memcpy() run-time warning in dg_dispatch_as_host()\n\nSyzkaller hit 'WARNING in dg_dispatch_as_host' bug.\n\nmemcpy: detected field-spanning write (size 56) of single field \"&dg_info->msg\"\nat drivers/misc/vmw_vmci/vmci_datagram.c:237 (size 24)\n\nWARNING: CPU: 0 PID: 1555 at drivers/misc/vmw_vmci/vmci_datagram.c:237\ndg_dispatch_as_host+0x88e/0xa60 drivers/misc/vmw_vmci/vmci_datagram.c:237\n\nSome code commentry, based on my understanding:\n\n544 #define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size)\n/// This is 24 + payload_size\n\nmemcpy(&dg_info->msg, dg, dg_size);\n\tDestination = dg_info->msg ---> this is a 24 byte\n\t\t\t\t\tstructure(struct vmci_datagram)\n\tSource = dg --> this is a 24 byte structure (struct vmci_datagram)\n\tSize = dg_size = 24 + payload_size\n\n{payload_size = 56-24 =32} -- Syzkaller managed to set payload_size to 32.\n\n 35 struct delayed_datagram_info {\n 36 struct datagram_entry *entry;\n 37 struct work_struct work;\n 38 bool in_dg_host_queue;\n 39 /* msg and msg_payload must be together. */\n 40 struct vmci_datagram msg;\n 41 u8 msg_payload[];\n 42 };\n\nSo those extra bytes of payload are copied into msg_payload[], a run time\nwarning is seen while fuzzing with Syzkaller.\n\nOne possible way to fix the warning is to split the memcpy() into\ntwo parts -- one -- direct assignment of msg and second taking care of payload.\n\nGustavo quoted:\n\"Under FORTIFY_SOURCE we should not copy data across multiple members\nin a structure.\""}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: VMCI: corrigi\u00f3 la advertencia de tiempo de ejecuci\u00f3n de memcpy() en dg_dispatch_as_host() Syzkaller presion\u00f3 el error 'ADVERTENCIA en dg_dispatch_as_host'. memcpy: se detect\u00f3 escritura que abarca todos los campos (tama\u00f1o 56) de un solo campo \"&dg_info->msg\" en drivers/misc/vmw_vmci/vmci_datagram.c:237 (tama\u00f1o 24) ADVERTENCIA: CPU: 0 PID: 1555 en drivers/misc/vmw_vmci /vmci_datagram.c:237 dg_dispatch_as_host+0x88e/0xa60 drivers/misc/vmw_vmci/vmci_datagram.c:237 Algunos comentarios de c\u00f3digo, seg\u00fan tengo entendido: 544 #define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size ) /// Esto es 24 + payload_size memcpy(&dg_info->msg, dg, dg_size); Destino = dg_info->msg ---> esta es una estructura de 24 bytes (struct vmci_datagram) Fuente = dg --> esta es una estructura de 24 bytes (struct vmci_datagram) Tama\u00f1o = dg_size = 24 + payload_size {payload_size = 56-24 = 32} -- Syzkaller logr\u00f3 establecer payload_size en 32. 35 struct delay_datagram_info { 36 struct datagram_entry *entry; 37 struct work_struct work; 38 bool in_dg_host_queue; 39 /* msg y msg_payload deben estar juntos. */ 40 struct vmci_datagram mensaje; 41 u8 msg_payload[]; 42}; Entonces, esos bytes adicionales de payload se copian en msg_payload[], se ve una advertencia de tiempo de ejecuci\u00f3n mientras se utiliza Syzkaller. Una forma posible de solucionar la advertencia es dividir memcpy() en dos partes: una, asignaci\u00f3n directa del mensaje y la segunda, encargada del payload. Gustavo cit\u00f3: \"Bajo FORTIFY_SOURCE no debemos copiar datos entre varios miembros de una estructura\"."}], "lastModified": "2025-12-17T03:38:40.920", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "23F858DD-6739-4BD9-9DA9-A9F5F66187C0", "versionEndExcluding": "4.19.312"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F45A0F3C-C16D-49C4-86D6-D021C3D4B834", "versionEndExcluding": "5.4.274", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9CD5894E-58E9-4B4A-B0F4-3E6BC134B8F5", "versionEndExcluding": "5.10.215", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F11B6314-A852-4FBD-AD84-ECE23F5C092B", "versionEndExcluding": "5.15.155", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F5D13FF4-8931-475F-A397-FD0594589F56", "versionEndExcluding": "6.1.86", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "41504EFE-0C3F-4B7C-B855-EFE4FA9ACB84", "versionEndExcluding": "6.6.27", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "22CA5433-1303-41EF-AD4C-F4645DC01541", "versionEndExcluding": "6.8.6", "versionStartIncluding": "6.7"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}