CVE-2026-99168

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Check per-CPU register page before mmap Register-page setup is optional for each CPU. If allocation or registration fails, mshv_vtl_configure_reg_page() warns and leaves that CPU's reg_page NULL, but initial context setup continues successfully. Meanwhile, successful setup on another CPU sets the global mshv_has_reg_page flag. mshv_vtl_fault() checks this global flag before selecting the requested CPU's register page. With mixed setup results across online CPUs, the check passes even for a CPU with no register page, reaching get_page(NULL) when userspace faults in that mapping. Check the selected per-CPU register page before taking its reference and return VM_FAULT_SIGBUS if it is absent.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-28 11:17:37.290000

Last modified

2026-10-28 11:17:37.290000

View original CVE JSON

{
  "id": "CVE-2026-99168",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-28T11:17:37.290",
  "lastModified": "2026-10-28T11:17:37.290",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv_vtl: Check per-CPU register page before mmap\n\nRegister-page setup is optional for each CPU. If allocation or\nregistration fails, mshv_vtl_configure_reg_page() warns and leaves that\nCPU's reg_page NULL, but initial context setup continues successfully.\nMeanwhile, successful setup on another CPU sets the global\nmshv_has_reg_page flag.\n\nmshv_vtl_fault() checks this global flag before selecting the requested\nCPU's register page. With mixed setup results across online CPUs, the\ncheck passes even for a CPU with no register page, reaching\nget_page(NULL) when userspace faults in that mapping.\n\nCheck the selected per-CPU register page before taking its reference and\nreturn VM_FAULT_SIGBUS if it is absent."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/hv/mshv_vtl_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f",
              "lessThan": "5c0757b065fbd140d8fbd05dc2c2146b713dfa68",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f",
              "lessThan": "874194a8de75fc2f4d1fb70c670b289b7e48f93e",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/hv/mshv_vtl_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.19",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.19",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.13",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/5c0757b065fbd140d8fbd05dc2c2146b713dfa68",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/874194a8de75fc2f4d1fb70c670b289b7e48f93e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}