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GHSA-J7PF-235F-JCQV

Vulnerability from github – Published: 2026-08-22 18:30 – Updated: 2026-08-25 06:31

Details

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

vhost-scsi: Validate T10 PI scatterlist counts

When T10 PI is negotiated, vhost-scsi splits protection bytes from the data iterator before mapping the request scatterlists. A malformed request can claim protection bytes that cover or exceed the full payload length. The former leaves no data bytes to map, while the latter underflows exp_data_len before advancing the iterator. Both cases can let a zero data SGL count reach sg_alloc_table_chained(), which triggers BUG_ON(!nents).

Reject protection lengths that cover or exceed the payload before subtracting prot_bytes and advancing the iterator. Also propagate negative errors from the protection SGL calculation before calling the allocator, matching the data SGL path.

Severity

7.1 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74703"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-22T16:16:44Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-scsi: Validate T10 PI scatterlist counts\n\nWhen T10 PI is negotiated, vhost-scsi splits protection bytes from\nthe data iterator before mapping the request scatterlists. A malformed\nrequest can claim protection bytes that cover or exceed the full payload\nlength. The former leaves no data bytes to map, while the latter\nunderflows exp_data_len before advancing the iterator. Both cases can let\na zero data SGL count reach sg_alloc_table_chained(), which triggers\nBUG_ON(!nents).\n\nReject protection lengths that cover or exceed the payload before\nsubtracting prot_bytes and advancing the iterator. Also propagate\nnegative errors from the protection SGL calculation before calling the\nallocator, matching the data SGL path.",
  "id": "GHSA-j7pf-235f-jcqv",
  "modified": "2026-08-25T06:31:28Z",
  "published": "2026-08-22T18:30:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74703"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2417a498cf3fe64d06faf87e236eda98dd4f04e0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d876c493fc4b811941bfeb4c80beb2dfc4bf025e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f8fe3f8d342da750dd10361bf66009fd3072926b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74703 (GCVE-0-2026-74703)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:33 – Updated: 2026-08-25 05:41

Title

vhost-scsi: Validate T10 PI scatterlist counts

Summary

In the Linux kernel, the following vulnerability has been resolved: vhost-scsi: Validate T10 PI scatterlist counts When T10 PI is negotiated, vhost-scsi splits protection bytes from the data iterator before mapping the request scatterlists. A malformed request can claim protection bytes that cover or exceed the full payload length. The former leaves no data bytes to map, while the latter underflows exp_data_len before advancing the iterator. Both cases can let a zero data SGL count reach sg_alloc_table_chained(), which triggers BUG_ON(!nents). Reject protection lengths that cover or exceed the payload before subtracting prot_bytes and advancing the iterator. Also propagate negative errors from the protection SGL calculation before calling the allocator, matching the data SGL path.

Severity

7.1 (High)


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

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/2417a498cf3fe64d0…
https://git.kernel.org/stable/c/f8fe3f8d342da750d…
https://git.kernel.org/stable/c/d876c493fc4b81194…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bca939d5bcd00d6faea99c47eafd60bed573ef03 , < 2417a498cf3fe64d06faf87e236eda98dd4f04e0 (git) Affected: bca939d5bcd00d6faea99c47eafd60bed573ef03 , < f8fe3f8d342da750dd10361bf66009fd3072926b (git) Affected: bca939d5bcd00d6faea99c47eafd60bed573ef03 , < d876c493fc4b811941bfeb4c80beb2dfc4bf025e (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.45 , ≤ 6.18.* (semver) Unaffected: 7.1.9 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/vhost/scsi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2417a498cf3fe64d06faf87e236eda98dd4f04e0",
              "status": "affected",
              "version": "bca939d5bcd00d6faea99c47eafd60bed573ef03",
              "versionType": "git"
            },
            {
              "lessThan": "f8fe3f8d342da750dd10361bf66009fd3072926b",
              "status": "affected",
              "version": "bca939d5bcd00d6faea99c47eafd60bed573ef03",
              "versionType": "git"
            },
            {
              "lessThan": "d876c493fc4b811941bfeb4c80beb2dfc4bf025e",
              "status": "affected",
              "version": "bca939d5bcd00d6faea99c47eafd60bed573ef03",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/vhost/scsi.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": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "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": "6.18.45",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.9",
                  "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\nvhost-scsi: Validate T10 PI scatterlist counts\n\nWhen T10 PI is negotiated, vhost-scsi splits protection bytes from\nthe data iterator before mapping the request scatterlists. A malformed\nrequest can claim protection bytes that cover or exceed the full payload\nlength. The former leaves no data bytes to map, while the latter\nunderflows exp_data_len before advancing the iterator. Both cases can let\na zero data SGL count reach sg_alloc_table_chained(), which triggers\nBUG_ON(!nents).\n\nReject protection lengths that cover or exceed the payload before\nsubtracting prot_bytes and advancing the iterator. Also propagate\nnegative errors from the protection SGL calculation before calling the\nallocator, matching the data SGL path."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - A malicious KVM guest reaches vhost_scsi_handle_vq() by kicking the virtio-scsi I/O virtqueue; vhost_get_vq_desc() and copy_from_iter_full() pull a guest-controlled virtio_scsi_cmd_req_pi header into the host kernel, not via any network-facing protocol.\nAC:L - With VIRTIO_SCSI_F_T10_PI negotiated, the guest fully controls pi_bytesout/pi_bytesin and descriptor payload sizes; setting protection bytes to cover or exceed the payload deterministically leaves zero data SGL entries and hits BUG_ON(!nents) without races or uncontrollable memory layout.\nPR:N - No host root or capabilities are required; a malicious VM tenant only needs code execution inside a guest with an active virtio-scsi/vhost-scsi endpoint (standard QEMU/KVM+LIO passthrough), matching other guest-to-host virtio/KVM CNA scores for cloud multi-tenant hosts.\nUI:N - No separate victim action is needed; the attacker submits crafted virtio-scsi requests and kicks the virtqueue from their own guest workload without requiring a host administrator or another user to mount storage or perform any interactive step.\nS:C - Guest-supplied virtio-scsi T10 PI requests trigger BUG_ON(!nents) in host sg_alloc_table_chained() during vhost_scsi_mapal(), panicking the physical host kernel and crossing the KVM guest-to-host virtualization security boundary.\nC:N - The failure mode is an explicit BUG_ON(!nents) on zero scatterlist count; there is no demonstrated out-of-bounds read, use-after-free, or other memory corruption before the panic that could disclose host kernel data.\nI:N - No guest-controlled host memory write or control-flow hijack occurs; the host kernel aborts via BUG_ON before target_submit_prep(), and the bug is invalid scatterlist accounting rather than exploitable heap corruption.\nA:H - BUG_ON(!nents) in sg_alloc_table_chained() provokes a host kernel oops/panic in the vhost worker during guest virtio-scsi I/O, denying availability of the hypervisor and all co-resident VMs; the attack is reliably repeatable with crafted PI headers."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T05:41:46.287Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/2417a498cf3fe64d06faf87e236eda98dd4f04e0"
        },
        {
          "url": "https://git.kernel.org/stable/c/f8fe3f8d342da750dd10361bf66009fd3072926b"
        },
        {
          "url": "https://git.kernel.org/stable/c/d876c493fc4b811941bfeb4c80beb2dfc4bf025e"
        }
      ],
      "title": "vhost-scsi: Validate T10 PI scatterlist counts",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74703",
    "datePublished": "2026-08-22T15:33:02.872Z",
    "dateReserved": "2026-08-15T05:44:03.927Z",
    "dateUpdated": "2026-08-25T05:41:46.287Z",
    "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.

Detection rules are retrieved from Rulezet.

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-J7PF-235F-JCQV

CVE-2026-74703 (GCVE-0-2026-74703)

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Sightings

Nomenclature