{
  "id": "CVE-2024-42063",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-07-29T16:15:06.053",
  "lastModified": "2024-09-05T17:42:12.670",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode\n\nsyzbot reported uninit memory usages during map_{lookup,delete}_elem.\n\n==========\nBUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]\nBUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796\n__dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]\ndev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796\n____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline]\nbpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38\n___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997\n__bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237\n==========\n\nThe reproducer should be in the interpreter mode.\n\nThe C reproducer is trying to run the following bpf prog:\n\n    0: (18) r0 = 0x0\n    2: (18) r1 = map[id:49]\n    4: (b7) r8 = 16777216\n    5: (7b) *(u64 *)(r10 -8) = r8\n    6: (bf) r2 = r10\n    7: (07) r2 += -229\n            ^^^^^^^^^^\n\n    8: (b7) r3 = 8\n    9: (b7) r4 = 0\n   10: (85) call dev_map_lookup_elem#1543472\n   11: (95) exit\n\nIt is due to the \"void *key\" (r2) passed to the helper. bpf allows uninit\nstack memory access for bpf prog with the right privileges. This patch\nuses kmsan_unpoison_memory() to mark the stack as initialized.\n\nThis should address different syzbot reports on the uninit \"void *key\"\nargument during map_{lookup,delete}_elem."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: bpf: marcar la pila de programas bpf con kmsan_unposion_memory en modo int\u00e9rprete syzbot inform\u00f3 usos de memoria uninit durante map_{lookup,delete}_elem. ========== ERROR: KMSAN: valor uninit en __dev_map_lookup_elem kernel/bpf/devmap.c:441 [en l\u00ednea] ERROR: KMSAN: valor uninit en dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap. c:796 __dev_map_lookup_elem kernel/bpf/devmap.c:441 [en l\u00ednea] dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 ____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [en l\u00ednea] bpf_map_lookup_elem+0x5c/0x80 kernel / bpf/helpers.c:38 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237 ========== El reproductor debe estar en el modo int\u00e9rprete. El reproductor de C est\u00e1 intentando ejecutar el siguiente programa bpf: 0: (18) r0 = 0x0 2: (18) r1 = map[id:49] 4: (b7) r8 = 16777216 5: (7b) *(u64 * )(r10 -8) = r8 6: (bf) r2 = r10 7: (07) r2 += -229 ^^^^^^^^^^ 8: (b7) r3 = 8 9: (b7) r4 = 0 10: (85) llamar a dev_map_lookup_elem#1543472 11: (95) salir Se debe a la \"clave * vac\u00eda\" (r2) pasada al ayudante. bpf permite el acceso a la memoria de pila uninit para el programa bpf con los privilegios correctos. Este parche usa kmsan_unpoison_memory() para marcar la pila como inicializada. Esto deber\u00eda abordar diferentes informes de syzbot sobre el argumento uninit \"void *key\" durante map_{lookup,delete}_elem."
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-908"
        }
      ]
    }
  ],
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          "negate": false,
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