nvd-json-data-feeds/CVE-2022/CVE-2022-487xx/CVE-2022-48731.json

{
  "id": "CVE-2022-48731",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-06-20T12:15:11.517",
  "lastModified": "2024-11-21T07:33:53.020",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/kmemleak: avoid scanning potential huge holes\n\nWhen using devm_request_free_mem_region() and devm_memremap_pages() to\nadd ZONE_DEVICE memory, if requested free mem region's end pfn were\nhuge(e.g., 0x400000000), the node_end_pfn() will be also huge (see\nmove_pfn_range_to_zone()).  Thus it creates a huge hole between\nnode_start_pfn() and node_end_pfn().\n\nWe found on some AMD APUs, amdkfd requested such a free mem region and\ncreated a huge hole.  In such a case, following code snippet was just\ndoing busy test_bit() looping on the huge hole.\n\n  for (pfn = start_pfn; pfn < end_pfn; pfn++) {\n\tstruct page *page = pfn_to_online_page(pfn);\n\t\tif (!page)\n\t\t\tcontinue;\n\t...\n  }\n\nSo we got a soft lockup:\n\n  watchdog: BUG: soft lockup - CPU#6 stuck for 26s! [bash:1221]\n  CPU: 6 PID: 1221 Comm: bash Not tainted 5.15.0-custom #1\n  RIP: 0010:pfn_to_online_page+0x5/0xd0\n  Call Trace:\n    ? kmemleak_scan+0x16a/0x440\n    kmemleak_write+0x306/0x3a0\n    ? common_file_perm+0x72/0x170\n    full_proxy_write+0x5c/0x90\n    vfs_write+0xb9/0x260\n    ksys_write+0x67/0xe0\n    __x64_sys_write+0x1a/0x20\n    do_syscall_64+0x3b/0xc0\n    entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nI did some tests with the patch.\n\n(1) amdgpu module unloaded\n\nbefore the patch:\n\n  real    0m0.976s\n  user    0m0.000s\n  sys     0m0.968s\n\nafter the patch:\n\n  real    0m0.981s\n  user    0m0.000s\n  sys     0m0.973s\n\n(2) amdgpu module loaded\n\nbefore the patch:\n\n  real    0m35.365s\n  user    0m0.000s\n  sys     0m35.354s\n\nafter the patch:\n\n  real    0m1.049s\n  user    0m0.000s\n  sys     0m1.042s"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm/kmemleak: evita escanear posibles agujeros enormes. Al usar devm_request_free_mem_region() y devm_memremap_pages() para agregar memoria ZONE_DEVICE, si se solicitaba, el pfn final de la regi\u00f3n de memoria libre era enorme (por ejemplo, 0x400000000), el node_end_pfn() tambi\u00e9n ser\u00e1 enorme (ver move_pfn_range_to_zone()). Por lo tanto, crea un enorme agujero entre node_start_pfn() y node_end_pfn(). Descubrimos que en algunas APU AMD, AMDKFD solicit\u00f3 una regi\u00f3n de memoria libre y cre\u00f3 un agujero enorme. En tal caso, el siguiente fragmento de c\u00f3digo simplemente estaba haciendo un bucle test_bit() ocupado en el enorme agujero. for (pfn = start_pfn; pfn &lt; end_pfn; pfn++) { estructura p\u00e1gina *p\u00e1gina = pfn_to_online_page(pfn); si (!p\u00e1gina) contin\u00faa; ... } Entonces obtuvimos un bloqueo suave: perro guardi\u00e1n: ERROR: bloqueo suave - \u00a1CPU#6 bloqueada durante 26 segundos! [bash:1221] CPU: 6 PID: 1221 Comm: bash No contaminado 5.15.0-custom #1 RIP: 0010:pfn_to_online_page+0x5/0xd0 Seguimiento de llamadas:? kmemleak_scan+0x16a/0x440 kmemleak_write+0x306/0x3a0 ? common_file_perm+0x72/0x170 full_proxy_write+0x5c/0x90 vfs_write+0xb9/0x260 ksys_write+0x67/0xe0 __x64_sys_write+0x1a/0x20 do_syscall_64+0x3b/0xc0 Entry_SYSCALL_64_after_hwframe+0x4 4/0xae Hice algunas pruebas con el parche. (1) m\u00f3dulo amdgpu descargado antes del parche: usuario real 0m0.976s 0m0.000s sys 0m0.968s despu\u00e9s del parche: usuario real 0m0.981s 0m0.000s sys 0m0.973s (2) m\u00f3dulo amdgpu cargado antes del parche: real 0m35 .365s usuario 0m0.000s sys 0m35.354s despu\u00e9s del parche: real 0m1.049s usuario 0m0.000s sys 0m1.042s"
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/352715593e81b917ce1b321e794549815b850134",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a5389c80992f0001ee505838fe6a8b20897ce96e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c10a0f877fe007021d70f9cada240f42adc2b5db",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cebb0aceb21ad91429617a40e3a17444fabf1529",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d3533ee20e9a0e2e8f60384da7450d43d1c63d1a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/352715593e81b917ce1b321e794549815b850134",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/a5389c80992f0001ee505838fe6a8b20897ce96e",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/c10a0f877fe007021d70f9cada240f42adc2b5db",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/cebb0aceb21ad91429617a40e3a17444fabf1529",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/d3533ee20e9a0e2e8f60384da7450d43d1c63d1a",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ]
}