Vulnerability-Lookup

GHSA-444C-98P8-5JQ5

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Fix RB-tree corruption in probe error path

The info->node RB-tree member is zero-initialized via kzalloc. If a device does not support ATS, the device_rbtree_insert() call is skipped. If a subsequent probe step fails, the error path jumps to device_rbtree_remove(), which misinterprets the zeroed node as a tree root and corrupts the device RB-tree.

Fix this by explicitly initializing the RB-node as empty using RB_CLEAR_NODE() during initialization and guarding the removal with RB_EMPTY_NODE().

Severity

8.2 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74355"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:36Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Fix RB-tree corruption in probe error path\n\nThe info-\u003enode RB-tree member is zero-initialized via kzalloc. If\na device does not support ATS, the device_rbtree_insert() call is\nskipped. If a subsequent probe step fails, the error path jumps to\ndevice_rbtree_remove(), which misinterprets the zeroed node as\na tree root and corrupts the device RB-tree.\n\nFix this by explicitly initializing the RB-node as empty using\nRB_CLEAR_NODE() during initialization and guarding the removal with\nRB_EMPTY_NODE().",
  "id": "GHSA-444c-98p8-5jq5",
  "modified": "2026-08-17T06:33:40Z",
  "published": "2026-08-15T06:32:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74355"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/43bd9e6d5513cb1edbafdeef146a1edc3aaced56"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d16923a45d4d08367650fdc3451c89299ab6ac5a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f5102e0fc3c6dc8685549891a96e4589fdb3e211"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74355 (GCVE-0-2026-74355)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:58 – Updated: 2026-08-17 05:46

Title

iommu/vt-d: Fix RB-tree corruption in probe error path

Summary

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix RB-tree corruption in probe error path The info->node RB-tree member is zero-initialized via kzalloc. If a device does not support ATS, the device_rbtree_insert() call is skipped. If a subsequent probe step fails, the error path jumps to device_rbtree_remove(), which misinterprets the zeroed node as a tree root and corrupts the device RB-tree. Fix this by explicitly initializing the RB-node as empty using RB_CLEAR_NODE() during initialization and guarding the removal with RB_EMPTY_NODE().

Severity

8.2 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Assigner

Linux mitre root Scorecard

References

3 references

URL	Tags
https://git.kernel.org/stable/c/f5102e0fc3c6dc868…
https://git.kernel.org/stable/c/d16923a45d4d08367…
https://git.kernel.org/stable/c/43bd9e6d5513cb1ed…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4f1492efb495bcef34c9ee8a94af81e6cea5abf4 , < f5102e0fc3c6dc8685549891a96e4589fdb3e211 (git) Affected: 4f1492efb495bcef34c9ee8a94af81e6cea5abf4 , < d16923a45d4d08367650fdc3451c89299ab6ac5a (git) Affected: 4f1492efb495bcef34c9ee8a94af81e6cea5abf4 , < 43bd9e6d5513cb1edbafdeef146a1edc3aaced56 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/intel/iommu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f5102e0fc3c6dc8685549891a96e4589fdb3e211",
              "status": "affected",
              "version": "4f1492efb495bcef34c9ee8a94af81e6cea5abf4",
              "versionType": "git"
            },
            {
              "lessThan": "d16923a45d4d08367650fdc3451c89299ab6ac5a",
              "status": "affected",
              "version": "4f1492efb495bcef34c9ee8a94af81e6cea5abf4",
              "versionType": "git"
            },
            {
              "lessThan": "43bd9e6d5513cb1edbafdeef146a1edc3aaced56",
              "status": "affected",
              "version": "4f1492efb495bcef34c9ee8a94af81e6cea5abf4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/intel/iommu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Fix RB-tree corruption in probe error path\n\nThe info-\u003enode RB-tree member is zero-initialized via kzalloc. If\na device does not support ATS, the device_rbtree_insert() call is\nskipped. If a subsequent probe step fails, the error path jumps to\ndevice_rbtree_remove(), which misinterprets the zeroed node as\na tree root and corrupts the device RB-tree.\n\nFix this by explicitly initializing the RB-node as empty using\nRB_CLEAR_NODE() during initialization and guarding the removal with\nRB_EMPTY_NODE()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is hit in intel_iommu_probe_device() during IOMMU device probing on the PCI bus notifier path (BUS_NOTIFY_ADD_DEVICE), which is only reachable via local kernel actions such as PCI hotplug/rescan, SR-IOV VF creation, or driver bind\u2014not via any network protocol.\nAC:L - A privileged attacker can reliably trigger the fault path by inducing PASID table allocation failure (e.g., memory pressure) while adding or reprobing a non-ATS PCI function on a VT-d scalable-mode host where ATS-capable devices may already populate the IOMMU device RB-tree.\nPR:H - Reaching intel_iommu_probe_device() requires adding or reprobing PCI/IOMMU devices through kernel-local administration (CAP_SYS_ADMIN for sysfs rescan/SR-IOV, or equivalent host control); this cannot be done from an unprivileged user or user namespace alone.\nUI:N - Exploitation does not depend on any victim user action beyond the attacker (or administrator) initiating device probe/hotplug; no interactive user steps are required once the privileged trigger is performed.\nS:C - Corrupting the Intel VT-d device RB-tree breaks RID-to-device tracking used for IOMMU page-request and invalidation handling, which can undermine DMA/IOMMU isolation boundaries (e.g., SR-IOV/assigned-device or host DMA containment), not just the probing process itself.\nC:H - Calling rb_erase() on a zero-initialized RB-node can null the tree root and corrupt kernel RB-tree pointers; such kernel memory corruption is exploitable to obtain arbitrary read primitives or leak sensitive kernel data during subsequent lookups.\nI:H - The erroneous rb_erase() performs out-of-tree pointer writes that corrupt IOMMU device tracking structures, providing a kernel memory corruption primitive that can be developed into arbitrary write or code execution.\nA:H - RB-tree corruption in the IOMMU device map can cause kernel oopses/panics during later device_rbtree_find() operations in interrupt-driven VT-d page-request or invalidation-timeout paths, resulting in complete loss of kernel availability."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:46:16.092Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f5102e0fc3c6dc8685549891a96e4589fdb3e211"
        },
        {
          "url": "https://git.kernel.org/stable/c/d16923a45d4d08367650fdc3451c89299ab6ac5a"
        },
        {
          "url": "https://git.kernel.org/stable/c/43bd9e6d5513cb1edbafdeef146a1edc3aaced56"
        }
      ],
      "title": "iommu/vt-d: Fix RB-tree corruption in probe error path",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74355",
    "datePublished": "2026-08-15T05:58:40.766Z",
    "dateReserved": "2026-08-15T05:44:03.887Z",
    "dateUpdated": "2026-08-17T05:46:16.092Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-444C-98P8-5JQ5

CVE-2026-74355 (GCVE-0-2026-74355)

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