← Back to CVE Explorer

CVE-2026-98713

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Apply the fine-grained UNDEFs without FEAT_FGT FGUs don't actually require hardware support, so don't gate fgt trap config insertion on FGT. This is the only action required to allow FGUs always, as kvm_calculate_traps() already computes the FGU bits with or without FEAT_FGT. This also fixes a spurious WARN when a TLBI OS is run on a guest in vEL1 without FEAT_TLBIOS on non FEAT_FGT hardware. In this configuration the course-grained HCR_EL2.TTLBOS trap reaches the handler handle_tlbi_el1(), which expects an EL1 TLBI only from vEL2. With FGUs enabled the UNDEF will be injected without needing the specific handler. [oliver: Take Wei-Lin's suggested changelog]

Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-18 16:17:24.857000
Last modified
2026-10-19 10:19:35.570000
View original CVE JSON
{
  "id": "CVE-2026-98713",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:24.857",
  "lastModified": "2026-10-19T10:19:35.570",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Apply the fine-grained UNDEFs without FEAT_FGT\n\nFGUs don't actually require hardware support, so don't gate fgt trap\nconfig insertion on FGT. This is the only action required to allow FGUs\nalways, as kvm_calculate_traps() already computes the FGU bits with or\nwithout FEAT_FGT.\n\nThis also fixes a spurious WARN when a TLBI OS is run on a guest in vEL1\nwithout FEAT_TLBIOS on non FEAT_FGT hardware. In this configuration the\ncourse-grained HCR_EL2.TTLBOS trap reaches the handler handle_tlbi_el1(),\nwhich expects an EL1 TLBI only from vEL2. With FGUs enabled the UNDEF\nwill be injected without needing the specific handler.\n\n[oliver: Take Wei-Lin's suggested changelog]"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "arch/arm64/kvm/emulate-nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "f5a5a406b4b8bb6c1fc7a1e92a872bd86061a53f",
              "lessThan": "2f4a15c52a552c5244ec27f4ca8bda855594f918",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f5a5a406b4b8bb6c1fc7a1e92a872bd86061a53f",
              "lessThan": "1113374a17d7f7d16b02ee0bbd9b1e7a60cbb087",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f5a5a406b4b8bb6c1fc7a1e92a872bd86061a53f",
              "lessThan": "af3300b3a6bace925a496f3520e171c07b999c72",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f5a5a406b4b8bb6c1fc7a1e92a872bd86061a53f",
              "lessThan": "4bdd2b3a708c1feb701cb8b62feb8ad2fd77bb07",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "arch/arm64/kvm/emulate-nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.9",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.9",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.113",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.56",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.10",
              "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/1113374a17d7f7d16b02ee0bbd9b1e7a60cbb087",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2f4a15c52a552c5244ec27f4ca8bda855594f918",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4bdd2b3a708c1feb701cb8b62feb8ad2fd77bb07",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/af3300b3a6bace925a496f3520e171c07b999c72",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}