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KVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: KVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid() kvmhv_emulate_tlbie_all_lpid() iterates the nested-guest IDR and drops mmu_lock before calling kvmhv_emulate_tlbie_lpid(), but does not hold a reference on the kvm_nested_guest pointer obtained from the IDR. A concurrent vCPU issuing a single-LPID tlbie (is=2, ric=2) can race through kvmhv_flush_nested() -> kvmhv_remove_nested() -> idr_remove / --refcnt -> kvmhv_release_nested() -> kfree(gp) in that window, leaving the iterating vCPU with a dangling pointer. The subsequent mutex_lock(&gp->tlb_lock) and accesses to gp->shadow_pgtable, gp->shadow_lpid and gp->l1_host all touch freed memory. The free path is fully L1-controlled. Fix this by incrementing gp->refcnt inside the loop before dropping mmu_lock, mirroring what kvmhv_get_nested() does, and releasing the reference with kvmhv_put_nested() after the per-guest work completes. This is the same get/put discipline already used at every other call site that drops mmu_lock while holding a nested-guest pointer.

Announced Source revision 1
Original source ↗

CVE-2026-98283

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-98283

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "e3b6b4661527e821ffbe3db83952fdb1e6e47c49",
        "lessThan": "4d8f7b1f586375df8bce23a0909566ad5e852259",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e3b6b4661527e821ffbe3db83952fdb1e6e47c49",
        "lessThan": "e37fba1ba69385cff2d0e60b371ee19e7d1852d1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e3b6b4661527e821ffbe3db83952fdb1e6e47c49",
        "lessThan": "24b634852413229bb8340d908b115c3365f3a247",
        "versionType": "git"
      },
      {
        "status": "affected",
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        "lessThan": "fbf69b7d0555ee83c871f58750770f74b7179ad1",
        "versionType": "git"
      },
      {
        "status": "affected",
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        "lessThan": "ec2d7a52b3996ae81131617b4afc0af31583c1b4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e3b6b4661527e821ffbe3db83952fdb1e6e47c49",
        "lessThan": "51938dfa8a51a4f85328413fca9b6e21f9d2d088",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "arch/powerpc/kvm/book3s_hv_nested.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.20"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.20",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.1.189",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.112",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.54",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.8",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "arch/powerpc/kvm/book3s_hv_nested.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98283

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#38361 · Revision 1
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Publisher date
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