Vulnerability-Lookup

GHSA-6WQ7-XHX5-P3VW

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:

crypto: ccp - Check for page allocation failure correctly in TIO

Sashiko notes:

if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it safe to pass it directly to page_address()?

On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might compute a deterministic but invalid, non-zero virtual address. The subsequent if (tio_status) check would then evaluate to true, and sev_tsm_init_locked() would dereference the invalid pointer.

Indeed, page_address(NULL) will return non-NULL garbage here. Fix this by checking the page allocation itself for NULL, not the resulting virtual address.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74403"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:42Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Check for page allocation failure correctly in TIO\n\nSashiko notes:\n\n\u003e if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it\n\u003e safe to pass it directly to page_address()?\n\u003e\n\u003e On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might\n\u003e compute a deterministic but invalid, non-zero virtual address. The\n\u003e subsequent if (tio_status) check would then evaluate to true, and\n\u003e sev_tsm_init_locked() would dereference the invalid pointer.\n\nIndeed, page_address(NULL) will return non-NULL garbage here. Fix this by\nchecking the page allocation itself for NULL, not the resulting virtual\naddress.",
  "id": "GHSA-6wq7-xhx5-p3vw",
  "modified": "2026-08-17T06:33:43Z",
  "published": "2026-08-15T06:32:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74403"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a8d5370eef00eca132a292b1901c9914c817e385"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74403 (GCVE-0-2026-74403)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:59 – Updated: 2026-08-17 05:46

Title

crypto: ccp - Check for page allocation failure correctly in TIO

Summary

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Check for page allocation failure correctly in TIO Sashiko notes: > if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it > safe to pass it directly to page_address()? > > On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might > compute a deterministic but invalid, non-zero virtual address. The > subsequent if (tio_status) check would then evaluate to true, and > sev_tsm_init_locked() would dereference the invalid pointer. Indeed, page_address(NULL) will return non-NULL garbage here. Fix this by checking the page allocation itself for NULL, not the resulting virtual address.

Severity

7.8 (High)


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

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/17e1aae19a06d9f6d…
https://git.kernel.org/stable/c/a8d5370eef00eca13…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4be423572da1f4c11f45168e3fafda870ddac9f8 , < 17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69 (git) Affected: 4be423572da1f4c11f45168e3fafda870ddac9f8 , < a8d5370eef00eca132a292b1901c9914c817e385 (git)
Linux	Linux	Affected: 6.19 Unaffected: 0 , < 6.19 (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/crypto/ccp/sev-dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69",
              "status": "affected",
              "version": "4be423572da1f4c11f45168e3fafda870ddac9f8",
              "versionType": "git"
            },
            {
              "lessThan": "a8d5370eef00eca132a292b1901c9914c817e385",
              "status": "affected",
              "version": "4be423572da1f4c11f45168e3fafda870ddac9f8",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/crypto/ccp/sev-dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.19"
            },
            {
              "lessThan": "6.19",
              "status": "unaffected",
              "version": "0",
              "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": "7.1.5",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Check for page allocation failure correctly in TIO\n\nSashiko notes:\n\n\u003e if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it\n\u003e safe to pass it directly to page_address()?\n\u003e\n\u003e On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might\n\u003e compute a deterministic but invalid, non-zero virtual address. The\n\u003e subsequent if (tio_status) check would then evaluate to true, and\n\u003e sev_tsm_init_locked() would dereference the invalid pointer.\n\nIndeed, page_address(NULL) will return non-NULL garbage here. Fix this by\nchecking the page allocation itself for NULL, not the resulting virtual\naddress."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The flaw is in __sev_snp_init_locked() reached only through sev_platform_init() via KVM_SEV_INIT/KVM_SEV_INIT2 ioctls on /dev/kvm or kernel boot init; SEV-TIO platform setup has no network-facing entry point.\nAC:L - An attacker who can trigger first-time SNP init (e.g. psp_init_on_probe=0) can concurrently exhaust host memory to force __snp_alloc_firmware_pages() to return NULL and reliably reach the faulty page_address(NULL) path.\nPR:L - Reaching this code requires opening /dev/kvm and issuing KVM SNP initialization ioctls, which needs CAP_SYS_ADMIN obtainable by an unprivileged user inside a user namespace.\nUI:N - Exploitation needs only attacker-initiated KVM ioctls or boot-time SNP initialization; no action by another user or victim is required.\nS:U - Impact is confined to the host kernel during SNP-TIO initialization (oops, memory corruption); it does not cross a VM, container, or IOMMU security boundary.\nC:H - page_address(NULL) yields a non-NULL direct-map pointer, so sev_tio_init_locked() dereferences invalid memory and passes a bogus physical address to PSP firmware via SEV_CMD_TIO_STATUS, enabling kernel memory disclosure.\nI:H - The invalid pointer causes unchecked reads/writes in sev_tio_init_locked() and may direct PSP firmware to write TIO status data to an unintended physical page, enabling exploitable memory corruption.\nA:H - Dereferencing the bogus page_address(NULL) result in sev_tsm_init_locked()/sev_tio_init_locked() can trigger a kernel oops or panic, crashing the host during SNP-TIO initialization."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:46:45.328Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69"
        },
        {
          "url": "https://git.kernel.org/stable/c/a8d5370eef00eca132a292b1901c9914c817e385"
        }
      ],
      "title": "crypto: ccp - Check for page allocation failure correctly in TIO",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74403",
    "datePublished": "2026-08-15T05:59:13.399Z",
    "dateReserved": "2026-08-15T05:44:03.892Z",
    "dateUpdated": "2026-08-17T05:46:45.328Z",
    "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-6WQ7-XHX5-P3VW

CVE-2026-74403 (GCVE-0-2026-74403)

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