CVE-2026-64460 (GCVE-0-2026-64460)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:51 – Updated: 2026-08-17 04:56
VLAI
Title
PCI/IOV: Skip VF Resizable BAR restore on read error
Summary
In the Linux kernel, the following vulnerability has been resolved: PCI/IOV: Skip VF Resizable BAR restore on read error sriov_restore_vf_rebar_state() uses the VF Resizable BAR Control register to decide how many VF BARs to restore (nbars) and which VF BAR each iteration addresses (bar_idx). bar_idx indexes into dev->sriov->barsz[], which has only PCI_SRIOV_NUM_BARS (6) entries. When a device does not respond, config reads typically return PCI_ERROR_RESPONSE (~0). Both fields are 3 bits wide, so nbars and bar_idx both evaluate to 7. The barsz[] access then goes out of bounds. UBSAN reports this as: UBSAN: array-index-out-of-bounds in drivers/pci/iov.c:948:51 index 7 is out of range for type 'resource_size_t [6]' Observed on an NVIDIA RTX PRO 1000 GPU (GB207GLM) that stopped responding during a failed GC6 power state exit. The subsequent pci_restore_state() invoked sriov_restore_vf_rebar_state() while config reads returned 0xffffffff, triggering the splat. Bail out if any VF Resizable BAR Control read returns PCI_ERROR_RESPONSE. No further VF BARs are touched, which is safe because a config read that returns PCI_ERROR_RESPONSE indicates the device is unreachable and restoration is pointless. This mirrors the guard in pci_restore_rebar_state().
Severity
7 (High)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 5a8f77e24a30bbce2fa57926f3dede84894fd10a , < b77524621250407386f44c6eea7e5e4619ada1ce (git)
Affected: 5a8f77e24a30bbce2fa57926f3dede84894fd10a , < 55fd485e66d0ad5c762c23dba1461fe9c741cd96 (git)
Affected: 5a8f77e24a30bbce2fa57926f3dede84894fd10a , < f34f1712229d71ce4286440fef12526fd4590b37 (git)
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Linux Linux Affected: 6.17
Unaffected: 0 , < 6.17 (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/pci/iov.c"
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          "vendor": "Linux",
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          "vendor": "Linux",
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              "version": "0",
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              "versionType": "semver"
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              "operator": "OR"
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      "descriptions": [
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nPCI/IOV: Skip VF Resizable BAR restore on read error\n\nsriov_restore_vf_rebar_state() uses the VF Resizable BAR Control register\nto decide how many VF BARs to restore (nbars) and which VF BAR each\niteration addresses (bar_idx). bar_idx indexes into dev-\u003esriov-\u003ebarsz[],\nwhich has only PCI_SRIOV_NUM_BARS (6) entries.\n\nWhen a device does not respond, config reads typically return\nPCI_ERROR_RESPONSE (~0).  Both fields are 3 bits wide, so nbars and bar_idx\nboth evaluate to 7. The barsz[] access then goes out of bounds.  UBSAN\nreports this as:\n\n  UBSAN: array-index-out-of-bounds in drivers/pci/iov.c:948:51 index 7 is out of range for type \u0027resource_size_t [6]\u0027\n\nObserved on an NVIDIA RTX PRO 1000 GPU (GB207GLM) that stopped responding\nduring a failed GC6 power state exit. The subsequent pci_restore_state()\ninvoked sriov_restore_vf_rebar_state() while config reads returned\n0xffffffff, triggering the splat.\n\nBail out if any VF Resizable BAR Control read returns PCI_ERROR_RESPONSE.\nNo further VF BARs are touched, which is safe because a config read that\nreturns PCI_ERROR_RESPONSE indicates the device is unreachable and\nrestoration is pointless. This mirrors the guard in\npci_restore_rebar_state()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H",
            "version": "3.1"
          },
          "scenarios": [
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              "lang": "en",
              "value": "AV:L - The flaw is reachable through local device operations, including DRM render-node runtime resume and delegated VFIO reset or power-management paths, rather than network packet processing.\nAC:H - Triggering the invalid index requires the SR-IOV PF to become PCI-inaccessible so configuration reads return 0xffffffff; the reported failed GC6 exit is a hardware or firmware failure the attacker cannot reliably control.\nPR:L - An ordinary user with DRM render-node or delegated VFIO access can initiate relevant resume or reset activity without a capability check; only the separate PCI sysfs reset path requires init-namespace root.\nUI:N - The attacker can initiate the device-use, resume, or reset sequence without any action by another user.\nS:C - In a VFIO PF-passthrough deployment, tenant-controlled device activity and VM teardown can reach host PCI restoration, so a resulting host oops or panic crosses the guest-to-host security boundary.\nC:L - The fixed index reads one resource_size_t immediately beyond the six-entry barsz array; it is not an arbitrary-read primitive, and only a heavily encoded BAR-size value could become observable if the device resumes.\nI:L - There is no kernel-memory write primitive, but the value derived from the out-of-bounds word is written to VF Resizable BAR control and could cause limited incorrect device configuration if the device becomes responsive.\nA:H - UBSAN trap, panic-on-warn, KASAN, or KFENCE configurations can turn the bounds violation into a host oops or panic, causing complete service loss."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:56:05.033Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/55fd485e66d0ad5c762c23dba1461fe9c741cd96"
        },
        {
          "url": "https://git.kernel.org/stable/c/f34f1712229d71ce4286440fef12526fd4590b37"
        }
      ],
      "title": "PCI/IOV: Skip VF Resizable BAR restore on read error",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64460",
    "datePublished": "2026-07-25T08:51:27.568Z",
    "dateReserved": "2026-07-19T15:36:31.789Z",
    "dateUpdated": "2026-08-17T04:56:05.033Z",
    "state": "PUBLISHED"
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      "date": "2026-09-25",
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      "percentile": "0.02762"
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        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nPCI/IOV: Skip VF Resizable BAR restore on read error\n\nsriov_restore_vf_rebar_state() uses the VF Resizable BAR Control register\nto decide how many VF BARs to restore (nbars) and which VF BAR each\niteration addresses (bar_idx). bar_idx indexes into dev-\u003esriov-\u003ebarsz[],\nwhich has only PCI_SRIOV_NUM_BARS (6) entries.\n\nWhen a device does not respond, config reads typically return\nPCI_ERROR_RESPONSE (~0).  Both fields are 3 bits wide, so nbars and bar_idx\nboth evaluate to 7. The barsz[] access then goes out of bounds.  UBSAN\nreports this as:\n\n  UBSAN: array-index-out-of-bounds in drivers/pci/iov.c:948:51 index 7 is out of range for type \u0027resource_size_t [6]\u0027\n\nObserved on an NVIDIA RTX PRO 1000 GPU (GB207GLM) that stopped responding\nduring a failed GC6 power state exit. The subsequent pci_restore_state()\ninvoked sriov_restore_vf_rebar_state() while config reads returned\n0xffffffff, triggering the splat.\n\nBail out if any VF Resizable BAR Control read returns PCI_ERROR_RESPONSE.\nNo further VF BARs are touched, which is safe because a config read that\nreturns PCI_ERROR_RESPONSE indicates the device is unreachable and\nrestoration is pointless. This mirrors the guard in\npci_restore_rebar_state()."
          }
        ],
        "id": "CVE-2026-64460",
        "lastModified": "2026-08-17T05:17:51.230",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
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                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.0,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "LOW",
                "scope": "CHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H",
                "version": "3.1"
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              "impactScore": 5.3,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
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        "published": "2026-07-25T10:17:31.193",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/55fd485e66d0ad5c762c23dba1461fe9c741cd96"
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          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-30T03:01:20+00:00",
      "cve": "CVE-2026-64460",
      "id": "CVE-2026-64460",
      "initial_release_date": "2026-07-25T00:00:00+00:00",
      "product_status:known_affected": "198",
      "product_status:known_not_affected": "76",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: PCI/IOV: Skip VF Resizable BAR restore on read error",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64460.json",
      "version": "3"
    }
  }
}



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