cve/published/2021/CVE-2021-47450.json

{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "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's 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't, hence corrupting the page-table.\n\nFix this by introducing a new hyp_split_page() helper in the EL2 page\nallocator (matching the kernel's split_page() function), and make use of\nit from host_s2_zalloc_pages_exact()."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "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"
               ],
               "versions": [
                  {
                     "version": "1025c8c0c6accfcbdc8f52ca1940160f65cd87d6",
                     "lessThan": "b372264c66ef78f2cab44e877fbd765ad6d24c39",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1025c8c0c6accfcbdc8f52ca1940160f65cd87d6",
                     "lessThan": "1d58a17ef54599506d44c45ac95be27273a4d2b1",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "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"
               ],
               "versions": [
                  {
                     "version": "5.13",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.13",
                     "status": "unaffected",
                     "versionType": "semver"
                  },
                  {
                     "version": "5.14.15",
                     "lessThanOrEqual": "5.14.*",
                     "status": "unaffected",
                     "versionType": "semver"
                  },
                  {
                     "version": "5.15",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "cpeApplicability": [
            {
               "nodes": [
                  {
                     "operator": "OR",
                     "negate": false,
                     "cpeMatch": [
                        {
                           "vulnerable": true,
                           "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           "versionStartIncluding": "5.13",
                           "versionEndExcluding": "5.14.15"
                        },
                        {
                           "vulnerable": true,
                           "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           "versionStartIncluding": "5.13",
                           "versionEndExcluding": "5.15"
                        }
                     ]
                  }
               ]
            }
         ],
         "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-1.2.0"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47450",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}