Vulnerability-Lookup

GHSA-R2VM-Q278-6VPV

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31

Details

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

net: mana: validate rx_req_idx to prevent out-of-bounds array access

In mana_hwc_rx_event_handler(), rx_req_idx is derived from sge->address in DMA-coherent memory. In Confidential VMs (SEV-SNP/TDX), this memory is shared unencrypted and HW can modify WQE contents at any time. No bounds check exists on rx_req_idx, which can lead to an out-of-bounds access into reqs[].

Add bounds check on rx_req_idx in mana_hwc_rx_event_handler() before using it to index the reqs[] array.

Severity

9.3 (Critical)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64018"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:41Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: validate rx_req_idx to prevent out-of-bounds array access\n\nIn mana_hwc_rx_event_handler(), rx_req_idx is derived from\nsge-\u003eaddress in DMA-coherent memory. In Confidential VMs\n(SEV-SNP/TDX), this memory is shared unencrypted and HW can modify\nWQE contents at any time. No bounds check exists on rx_req_idx,\nwhich can lead to an out-of-bounds access into reqs[].\n\nAdd bounds check on rx_req_idx in mana_hwc_rx_event_handler() before\nusing it to index the reqs[] array.",
  "id": "GHSA-r2vm-q278-6vpv",
  "modified": "2026-07-20T15:31:55Z",
  "published": "2026-07-19T18:31:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64018"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/355e9f2b2a7887ca38100127989af3e422ba71d0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5ddc715324badd7f2641bc177db1d027b402adae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/763a372d344fb12fae566d36ddb46e92454ad58c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b809d0409991b75a6cff846a5ac27c3062953f84"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fa627a5eaa83fc0261f44ef3769693b886ca6e27"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff1d5af207bcea857d45fe81505f1bc4b29eaef0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64018 (GCVE-0-2026-64018)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-08-05 12:38

Title

net: mana: validate rx_req_idx to prevent out-of-bounds array access

Summary

In the Linux kernel, the following vulnerability has been resolved: net: mana: validate rx_req_idx to prevent out-of-bounds array access In mana_hwc_rx_event_handler(), rx_req_idx is derived from sge->address in DMA-coherent memory. In Confidential VMs (SEV-SNP/TDX), this memory is shared unencrypted and HW can modify WQE contents at any time. No bounds check exists on rx_req_idx, which can lead to an out-of-bounds access into reqs[]. Add bounds check on rx_req_idx in mana_hwc_rx_event_handler() before using it to index the reqs[] array.

Severity

9.3 (Critical)


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

Assigner

Linux mitre root

References

7 references

URL	Tags
https://git.kernel.org/stable/c/5ddc715324badd7f2…
https://git.kernel.org/stable/c/ff1d5af207bcea857…
https://git.kernel.org/stable/c/01f7f893d5e1baae9…
https://git.kernel.org/stable/c/763a372d344fb12fa…
https://git.kernel.org/stable/c/fa627a5eaa83fc026…
https://git.kernel.org/stable/c/355e9f2b2a7887ca3…
https://git.kernel.org/stable/c/b809d0409991b75a6…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 5ddc715324badd7f2641bc177db1d027b402adae (git) Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < ff1d5af207bcea857d45fe81505f1bc4b29eaef0 (git) Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01 (git) Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 763a372d344fb12fae566d36ddb46e92454ad58c (git) Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < fa627a5eaa83fc0261f44ef3769693b886ca6e27 (git) Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 355e9f2b2a7887ca38100127989af3e422ba71d0 (git) Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < b809d0409991b75a6cff846a5ac27c3062953f84 (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 5.15.209 , ≤ 5.15.* (semver) Unaffected: 6.1.175 , ≤ 6.1.* (semver) Unaffected: 6.6.142 , ≤ 6.6.* (semver) Unaffected: 6.12.92 , ≤ 6.12.* (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/microsoft/mana/hw_channel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5ddc715324badd7f2641bc177db1d027b402adae",
              "status": "affected",
              "version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
              "versionType": "git"
            },
            {
              "lessThan": "ff1d5af207bcea857d45fe81505f1bc4b29eaef0",
              "status": "affected",
              "version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
              "versionType": "git"
            },
            {
              "lessThan": "01f7f893d5e1baae995beeb86cd0f3e6bb2a3b01",
              "status": "affected",
              "version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
              "versionType": "git"
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              "versionType": "git"
            },
            {
              "lessThan": "fa627a5eaa83fc0261f44ef3769693b886ca6e27",
              "status": "affected",
              "version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
              "versionType": "git"
            },
            {
              "lessThan": "355e9f2b2a7887ca38100127989af3e422ba71d0",
              "status": "affected",
              "version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
              "versionType": "git"
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              "status": "affected",
              "version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
              "versionType": "git"
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.209",
                  "versionStartIncluding": "5.13",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
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                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
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        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: validate rx_req_idx to prevent out-of-bounds array access\n\nIn mana_hwc_rx_event_handler(), rx_req_idx is derived from\nsge-\u003eaddress in DMA-coherent memory. In Confidential VMs\n(SEV-SNP/TDX), this memory is shared unencrypted and HW can modify\nWQE contents at any time. No bounds check exists on rx_req_idx,\nwhich can lead to an out-of-bounds access into reqs[].\n\nAdd bounds check on rx_req_idx in mana_hwc_rx_event_handler() before\nusing it to index the reqs[] array."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
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          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is reached via MSI-driven hardware completion processing in the MANA HWC control path (not netdev packet receive), triggered when the Azure hypervisor/host tampers with guest-visible DMA-coherent WQE memory on the same physical compute node.\nAC:L - A malicious host or NIC firmware that can modify shared unencrypted DMA buffers controls both the forged sge-\u003eaddress and the timing of HWC RX completions, allowing reliable out-of-bounds indexing without winning a race or depending on guest state.\nPR:N - Exploitation requires no privileges on the victim guest VM; the attacker operates from the Azure hypervisor/host side by modifying DMA-coherent memory that the guest kernel trusts during HWC response handling.\nUI:N - No victim user action is required; exploitation occurs automatically when the driver processes a hardware completion event on the HWC receive queue.\nS:C - In Confidential VMs the guest relies on host isolation guarantees, but shared unencrypted DMA memory lets a hostile hypervisor cross that CVM security boundary to corrupt guest kernel memory and confidentiality.\nC:H - An out-of-bounds rx_req_idx yields a corrupted hwc_work_request whose buf_va is dereferenced and copied via memcpy in mana_hwc_handle_resp(), enabling arbitrary kernel memory disclosure.\nI:H - The out-of-bounds hwc_work_request supplies attacker-controlled pointers and SGE fields used to repost RX WQEs via mana_hwc_post_rx_wqe(), enabling kernel heap corruption and exploitable memory writes.\nA:H - Indexing reqs[] out of bounds with attacker-controlled values can dereference invalid kernel pointers and corrupt adjacent heap objects, causing kernel oops/panic and denial of service."
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        "dateUpdated": "2026-08-05T12:38:15.556Z",
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        {
          "url": "https://git.kernel.org/stable/c/b809d0409991b75a6cff846a5ac27c3062953f84"
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      ],
      "title": "net: mana: validate rx_req_idx to prevent out-of-bounds array access",
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64018",
    "datePublished": "2026-07-19T15:39:12.704Z",
    "dateReserved": "2026-07-19T07:54:57.027Z",
    "dateUpdated": "2026-08-05T12:38:15.556Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-R2VM-Q278-6VPV

CVE-2026-64018 (GCVE-0-2026-64018)

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