cve-2021-47450
Vulnerability from cvelistv5
Published
2024-05-22 06:19
Modified
2024-08-04 05:39
Severity
Summary
KVM: arm64: Fix host stage-2 PGD refcount
References
SourceURLTags
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39
Impacted products
VendorProduct
LinuxLinux
LinuxLinux
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47450",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-05-22T18:46:22.813390Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-06-04T17:14:28.577Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:39:59.495Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/include/nvhe/gfp.h",
            "arch/arm64/kvm/hyp/nvhe/mem_protect.c",
            "arch/arm64/kvm/hyp/nvhe/page_alloc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b372264c66ef",
              "status": "affected",
              "version": "1025c8c0c6ac",
              "versionType": "git"
            },
            {
              "lessThan": "1d58a17ef545",
              "status": "affected",
              "version": "1025c8c0c6ac",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/include/nvhe/gfp.h",
            "arch/arm64/kvm/hyp/nvhe/mem_protect.c",
            "arch/arm64/kvm/hyp/nvhe/page_alloc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "5.14.*",
              "status": "unaffected",
              "version": "5.14.15",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix host stage-2 PGD refcount\n\nThe KVM page-table library refcounts the pages of concatenated stage-2\nPGDs individually. However, when running KVM in protected mode, the\nhost\u0027s stage-2 PGD is currently managed by EL2 as a single high-order\ncompound page, which can cause the refcount of the tail pages to reach 0\nwhen they shouldn\u0027t, hence corrupting the page-table.\n\nFix this by introducing a new hyp_split_page() helper in the EL2 page\nallocator (matching the kernel\u0027s split_page() function), and make use of\nit from host_s2_zalloc_pages_exact()."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-05-29T05:08:09.274Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39"
        },
        {
          "url": "https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1"
        }
      ],
      "title": "KVM: arm64: Fix host stage-2 PGD refcount",
      "x_generator": {
        "engine": "bippy-a5840b7849dd"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47450",
    "datePublished": "2024-05-22T06:19:41.443Z",
    "dateReserved": "2024-05-21T14:58:30.832Z",
    "dateUpdated": "2024-08-04T05:39:59.495Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-47450\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2024-05-22T07:15:10.143\",\"lastModified\":\"2024-05-22T12:46:53.887\",\"vulnStatus\":\"Awaiting Analysis\",\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nKVM: arm64: Fix host stage-2 PGD refcount\\n\\nThe KVM page-table library refcounts the pages of concatenated stage-2\\nPGDs individually. However, when running KVM in protected mode, the\\nhost\u0027s stage-2 PGD is currently managed by EL2 as a single high-order\\ncompound page, which can cause the refcount of the tail pages to reach 0\\nwhen they shouldn\u0027t, hence corrupting the page-table.\\n\\nFix this by introducing a new hyp_split_page() helper in the EL2 page\\nallocator (matching the kernel\u0027s split_page() function), and make use of\\nit from host_s2_zalloc_pages_exact().\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: KVM: arm64: corrige el recuento de PGD de etapa 2 del host La librer\u00eda de tablas de p\u00e1ginas de KVM vuelve a contar las p\u00e1ginas de los PGD de etapa 2 concatenados individualmente. Sin embargo, cuando se ejecuta KVM en modo protegido, EL2 administra actualmente el PGD de etapa 2 del host como una \u00fanica p\u00e1gina compuesta de alto orden, lo que puede causar que el recuento de las p\u00e1ginas finales llegue a 0 cuando no deber\u00eda, corrompiendo as\u00ed el tabla de p\u00e1ginas. Solucione este problema introduciendo un nuevo asistente hyp_split_page() en el asignador de p\u00e1ginas EL2 (que coincida con la funci\u00f3n split_page() del kernel) y util\u00edcelo desde host_s2_zalloc_pages_exact().\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.