FKIE_CVE-2026-74607

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-25 06:18
Severity
8.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Serialize accesses to the owner and mirror list with separate lock Interaction between KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM and KVM_CAP_VM_COPY_ENC_CONTEXT_FROM can cause two separate issues: - in sev_migrate_from(), when the destination KVM is a mirror, the mirror entry is moved from the source's list to the owner's mirror_vms list, without holding the owner's lock unlike other writers of the owner's mirror list (sev_vm_copy_enc_context_from(), sev_vm_destroy()). A concurrent COPY or destroy can race with sev_migrate_from() and corrupt the list. - In sev_vm_destroy(), the *owner* is still active and could receive concurrently a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM that causes sev->enc_context_owner to change. In this case the incorrect VM receives kvm_put_kvm(). The second issue needs particular care because the owner could disappear altogether (even though the race window is impossibly small) between reading it and locking it. There is thus no way to perform the checks under the owner lock without putting struct kvm under SLAB_TYPESAFE_BY_RCU (which would allow kvm_get_kvm_safe() under RCU critical section). It is much simpler to just use a global lock, since the critical sections are so small and the new lock is always a leaf lock.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1d78d33275ef2a16c6d080910b291d0a97a0e613
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/28afde1edbd8b20058cbf4d75fb57876471ec334
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/328ab4fabe05af004d886659f8744076e320ddce
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/47976eaaf0a4eb46dade48b3246779090db9e3ec
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7943ec3a6d0e7e0a2eb4943300bce089ac3e8c3e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d728baba0f20e49439fc7831bf3e4e7dee82161a
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/sev.c",
            "arch/x86/kvm/svm/svm.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "7943ec3a6d0e7e0a2eb4943300bce089ac3e8c3e",
              "status": "affected",
              "version": "b2125513dfc0dd0ec5a9605138a3c356592cfb73",
              "versionType": "git"
            },
            {
              "lessThan": "28afde1edbd8b20058cbf4d75fb57876471ec334",
              "status": "affected",
              "version": "b2125513dfc0dd0ec5a9605138a3c356592cfb73",
              "versionType": "git"
            },
            {
              "lessThan": "328ab4fabe05af004d886659f8744076e320ddce",
              "status": "affected",
              "version": "b2125513dfc0dd0ec5a9605138a3c356592cfb73",
              "versionType": "git"
            },
            {
              "lessThan": "47976eaaf0a4eb46dade48b3246779090db9e3ec",
              "status": "affected",
              "version": "b2125513dfc0dd0ec5a9605138a3c356592cfb73",
              "versionType": "git"
            },
            {
              "lessThan": "d728baba0f20e49439fc7831bf3e4e7dee82161a",
              "status": "affected",
              "version": "b2125513dfc0dd0ec5a9605138a3c356592cfb73",
              "versionType": "git"
            },
            {
              "lessThan": "1d78d33275ef2a16c6d080910b291d0a97a0e613",
              "status": "affected",
              "version": "b2125513dfc0dd0ec5a9605138a3c356592cfb73",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/sev.c",
            "arch/x86/kvm/svm/svm.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.153",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.105",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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: SVM: Serialize accesses to the owner and mirror list with separate lock\n\nInteraction between KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM and\nKVM_CAP_VM_COPY_ENC_CONTEXT_FROM can cause two separate issues:\n\n- in sev_migrate_from(), when the destination KVM is a mirror, the mirror\n  entry is moved from the source\u0027s list to the owner\u0027s mirror_vms list,\n  without holding the owner\u0027s lock unlike other writers of the owner\u0027s\n  mirror list (sev_vm_copy_enc_context_from(), sev_vm_destroy()).\n  A concurrent COPY or destroy can race with sev_migrate_from() and\n  corrupt the list.\n\n- In sev_vm_destroy(), the *owner* is still active and could receive\n  concurrently a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM that causes\n  sev-\u003eenc_context_owner to change.  In this case the incorrect VM\n  receives kvm_put_kvm().\n\nThe second issue needs particular care because the owner could disappear\naltogether (even though the race window is impossibly small) between\nreading it and locking it.  There is thus no way to perform the checks\nunder the owner lock without putting struct kvm under SLAB_TYPESAFE_BY_RCU\n(which would allow kvm_get_kvm_safe() under RCU critical section).\n\nIt is much simpler to just use a global lock, since the critical\nsections are so small and the new lock is always a leaf lock."
    }
  ],
  "id": "CVE-2026-74607",
  "lastModified": "2026-08-25T06:18:37.403",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:33.183",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1d78d33275ef2a16c6d080910b291d0a97a0e613"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/28afde1edbd8b20058cbf4d75fb57876471ec334"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/328ab4fabe05af004d886659f8744076e320ddce"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/47976eaaf0a4eb46dade48b3246779090db9e3ec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7943ec3a6d0e7e0a2eb4943300bce089ac3e8c3e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d728baba0f20e49439fc7831bf3e4e7dee82161a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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