fkie_cve-2021-47062
Vulnerability from fkie_nvd
Published
2024-02-29 23:15
Modified
2024-12-10 16:43
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs Use the kvm_for_each_vcpu() helper to iterate over vCPUs when encrypting VMSAs for SEV, which effectively switches to use online_vcpus instead of created_vcpus. This fixes a possible null-pointer dereference as created_vcpus does not guarantee a vCPU exists, since it is updated at the very beginning of KVM_CREATE_VCPU. created_vcpus exists to allow the bulk of vCPU creation to run in parallel, while still correctly restricting the max number of max vCPUs.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ba7bf5d6336aa9c0d977b161bfa420c56d46ee40Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bd0cced2ae93195668f983d443f7f17e8efd24d2Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c36b16d29f3af5f32fc1b2a3401bf48f71cabee1Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/ba7bf5d6336aa9c0d977b161bfa420c56d46ee40Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/bd0cced2ae93195668f983d443f7f17e8efd24d2Patch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/c36b16d29f3af5f32fc1b2a3401bf48f71cabee1Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *


To clipboard 

{
   configurations: [
      {
         nodes: [
            {
               cpeMatch: [
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "8CBB94EC-EC33-4464-99C5-03E5542715F0",
                     versionEndExcluding: "5.11.21",
                     versionStartIncluding: "5.11",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "D8C7052F-1B7B-4327-9C2B-84EBF3243838",
                     versionEndExcluding: "5.12.4",
                     versionStartIncluding: "5.12",
                     vulnerable: true,
                  },
               ],
               negate: false,
               operator: "OR",
            },
         ],
      },
   ],
   cveTags: [],
   descriptions: [
      {
         lang: "en",
         value: "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs\n\nUse the kvm_for_each_vcpu() helper to iterate over vCPUs when encrypting\nVMSAs for SEV, which effectively switches to use online_vcpus instead of\ncreated_vcpus.  This fixes a possible null-pointer dereference as\ncreated_vcpus does not guarantee a vCPU exists, since it is updated at\nthe very beginning of KVM_CREATE_VCPU.  created_vcpus exists to allow the\nbulk of vCPU creation to run in parallel, while still correctly\nrestricting the max number of max vCPUs.",
      },
      {
         lang: "es",
         value: "En el kernel de Linux, se resolvió la siguiente vulnerabilidad: KVM: SVM: use online_vcpus, no creado_vcpus, para iterar sobre vCPU. Use el asistente kvm_for_each_vcpu() para iterar sobre vCPU al cifrar VMSA para SEV, que efectivamente cambia para usar online_vcpus en lugar de creado_vcpus. Esto corrige una posible desreferencia de puntero nulo ya que create_vcpus no garantiza que exista una vCPU, ya que se actualiza al comienzo de KVM_CREATE_VCPU. create_vcpus existe para permitir que la mayor parte de la creación de vCPU se ejecute en paralelo, al mismo tiempo que restringe correctamente la cantidad máxima de vCPU máximas.",
      },
   ],
   id: "CVE-2021-47062",
   lastModified: "2024-12-10T16:43:41.337",
   metrics: {
      cvssMetricV31: [
         {
            cvssData: {
               attackComplexity: "LOW",
               attackVector: "LOCAL",
               availabilityImpact: "HIGH",
               baseScore: 5.5,
               baseSeverity: "MEDIUM",
               confidentialityImpact: "NONE",
               integrityImpact: "NONE",
               privilegesRequired: "LOW",
               scope: "UNCHANGED",
               userInteraction: "NONE",
               vectorString: "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
               version: "3.1",
            },
            exploitabilityScore: 1.8,
            impactScore: 3.6,
            source: "nvd@nist.gov",
            type: "Primary",
         },
      ],
   },
   published: "2024-02-29T23:15:07.843",
   references: [
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/ba7bf5d6336aa9c0d977b161bfa420c56d46ee40",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/bd0cced2ae93195668f983d443f7f17e8efd24d2",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/c36b16d29f3af5f32fc1b2a3401bf48f71cabee1",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/ba7bf5d6336aa9c0d977b161bfa420c56d46ee40",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/bd0cced2ae93195668f983d443f7f17e8efd24d2",
      },
      {
         source: "af854a3a-2127-422b-91ae-364da2661108",
         tags: [
            "Patch",
         ],
         url: "https://git.kernel.org/stable/c/c36b16d29f3af5f32fc1b2a3401bf48f71cabee1",
      },
   ],
   sourceIdentifier: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   vulnStatus: "Analyzed",
   weaknesses: [
      {
         description: [
            {
               lang: "en",
               value: "CWE-476",
            },
         ],
         source: "nvd@nist.gov",
         type: "Primary",
      },
   ],
}


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