CVE-2022-4994 (GCVE-0-2022-4994)

Vulnerability from cvelistv5 – Published: 2026-07-30 09:18 – Updated: 2026-07-30 09:18
VLAI
Title
KVM: x86: wean fast IN from emulator_pio_in
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: wean fast IN from emulator_pio_in Use __emulator_pio_in() directly for fast PIO instead of bouncing through emulator_pio_in() now that __emulator_pio_in() fills "val" when handling in-kernel PIO. vcpu->arch.pio.count is guaranteed to be '0', so this a pure nop. emulator_pio_in_emulated is now the last caller of emulator_pio_in. No functional change intended.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6641 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 8370c3d08bd98576d97514eca29970e03767a5d1 , < dc7a4bfde507ffe1d8bef49aba1322f1d20c2cb3 (git)
guessed Create a notification for this product.
Linux Linux Affected: 4.10
Unaffected: 0 , < 4.10 (semver)
Unaffected: 6.0 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/x86.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "dc7a4bfde507ffe1d8bef49aba1322f1d20c2cb3",
              "status": "affected",
              "version": "8370c3d08bd98576d97514eca29970e03767a5d1",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/x86.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.10"
            },
            {
              "lessThan": "4.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.0",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: wean fast IN from emulator_pio_in\n\nUse __emulator_pio_in() directly for fast PIO instead of bouncing through\nemulator_pio_in() now that __emulator_pio_in() fills \"val\" when handling\nin-kernel PIO.  vcpu-\u003earch.pio.count is guaranteed to be \u00270\u0027, so this a\npure nop.\n\nemulator_pio_in_emulated is now the last caller of emulator_pio_in.\n\nNo functional change intended."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-30T09:18:06.591Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/dc7a4bfde507ffe1d8bef49aba1322f1d20c2cb3"
        }
      ],
      "title": "KVM: x86: wean fast IN from emulator_pio_in",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2022-4994",
    "datePublished": "2026-07-30T09:18:06.591Z",
    "dateReserved": "2026-07-30T09:16:34.860Z",
    "dateUpdated": "2026-07-30T09:18:06.591Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2022-4994",
      "date": "2026-11-13",
      "epss": "0.0019",
      "percentile": "0.08764"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "arch/x86/kvm/x86.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "dc7a4bfde507ffe1d8bef49aba1322f1d20c2cb3",
                    "status": "affected",
                    "version": "8370c3d08bd98576d97514eca29970e03767a5d1",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "arch/x86/kvm/x86.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "4.10"
                  },
                  {
                    "lessThan": "4.10",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "6.0",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: wean fast IN from emulator_pio_in\n\nUse __emulator_pio_in() directly for fast PIO instead of bouncing through\nemulator_pio_in() now that __emulator_pio_in() fills \"val\" when handling\nin-kernel PIO.  vcpu-\u003earch.pio.count is guaranteed to be \u00270\u0027, so this a\npure nop.\n\nemulator_pio_in_emulated is now the last caller of emulator_pio_in.\n\nNo functional change intended."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nKVM: x86: destetar IN r\u00e1pido de emulator_pio_in\n\nUsar __emulator_pio_in() directamente para PIO r\u00e1pido en lugar de rebotar a trav\u00e9s de emulator_pio_in() ahora que __emulator_pio_in() llena \u2019val\u2019 al manejar PIO en el kernel. vcpu   -\u003e   arch.pio.count est\u00e1 garantizado de ser \u20190\u2019, por lo que esto es un nop puro.\n\nemulator_pio_in_emulated es ahora el \u00faltimo llamador de emulator_pio_in.\n\nNing\u00fan cambio funcional previsto."
          }
        ],
        "id": "CVE-2022-4994",
        "lastModified": "2026-11-10T12:10:00.177",
        "metrics": {},
        "published": "2026-07-30T10:16:34.270",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/dc7a4bfde507ffe1d8bef49aba1322f1d20c2cb3"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Undergoing Analysis"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-11-07T10:32:13+00:00",
      "cve": "CVE-2022-4994",
      "id": "CVE-2022-4994",
      "initial_release_date": "2022-01-01T00:00:00+00:00",
      "product_status:known_affected": "171",
      "product_status:known_not_affected": "29",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: KVM: x86: wean fast IN from emulator_pio_in",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2022/cve-2022-4994.json",
      "version": "3"
    }
  }
}



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