Vulnerability-Lookup

GHSA-24M2-RCHH-H2MX

Vulnerability from github – Published: 2026-06-08 18:31 – Updated: 2026-07-08 15:31

Details

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

drm/v3d: Reject empty multisync extension to prevent infinite loop

v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard:

if (se->in_sync_count || se->out_sync_count)
        return -EINVAL;

The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely.

Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector.

Severity

5.5 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-46314"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-08T17:16:50Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/v3d: Reject empty multisync extension to prevent infinite loop\n\nv3d_get_extensions() walks a userspace-provided singly-linked list of\nioctl extensions without any bound on the chain length. A local user\ncan craft a self-referential extension (ext-\u003enext == \u0026ext) with zero\nin_sync_count and out_sync_count, which bypasses the existing duplicate-\nextension guard:\n\n    if (se-\u003ein_sync_count || se-\u003eout_sync_count)\n            return -EINVAL;\n\nThe guard never fires because v3d_get_multisync_post_deps() returns\nimmediately when count is zero, leaving both fields at zero on every\niteration. The result is an infinite loop in kernel context, blocking\nthe calling thread and pegging a CPU core indefinitely.\n\nFix this by rejecting a multisync extension where both in_sync_count\nand out_sync_count are zero in v3d_get_multisync_submit_deps(). An\nempty multisync carries no synchronization information and serves no\nuseful purpose, so returning -EINVAL for such an extension is the\ncorrect defense against this attack vector.",
  "id": "GHSA-24m2-rchh-h2mx",
  "modified": "2026-07-08T15:31:37Z",
  "published": "2026-06-08T18:31:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46314"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/309abbddeca0c12714721928a819ef45e5710998"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-46314 (GCVE-0-2026-46314)

Vulnerability from cvelistv5 – Published: 2026-06-08 15:50 – Updated: 2026-06-19 12:00

Title

drm/v3d: Reject empty multisync extension to prevent infinite loop

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Reject empty multisync extension to prevent infinite loop v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard: if (se->in_sync_count || se->out_sync_count) return -EINVAL; The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely. Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/309abbddeca0c1271…
https://git.kernel.org/stable/c/4fa42a249e8cd6ed1…
https://git.kernel.org/stable/c/9c5164781cb388d21…
https://git.kernel.org/stable/c/fb44d589bf3148e13…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < 309abbddeca0c12714721928a819ef45e5710998 (git) Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < 4fa42a249e8cd6ed17aea04e5695b6e9001f2433 (git) Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < 9c5164781cb388d219d8f49fa0f0b04cf86ad544 (git) Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < fb44d589bf3148e13452185a6e772a7efbf2d684 (git)
Linux	Linux	Affected: 5.16 Unaffected: 0 , < 5.16 (semver) Unaffected: 6.1.176 , ≤ 6.1.* (semver) Unaffected: 6.18.33 , ≤ 6.18.* (semver) Unaffected: 7.0.9 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/v3d/v3d_submit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "309abbddeca0c12714721928a819ef45e5710998",
              "status": "affected",
              "version": "e4165ae8304e5ea822fbe5909dd3be5445c058b7",
              "versionType": "git"
            },
            {
              "lessThan": "4fa42a249e8cd6ed17aea04e5695b6e9001f2433",
              "status": "affected",
              "version": "e4165ae8304e5ea822fbe5909dd3be5445c058b7",
              "versionType": "git"
            },
            {
              "lessThan": "9c5164781cb388d219d8f49fa0f0b04cf86ad544",
              "status": "affected",
              "version": "e4165ae8304e5ea822fbe5909dd3be5445c058b7",
              "versionType": "git"
            },
            {
              "lessThan": "fb44d589bf3148e13452185a6e772a7efbf2d684",
              "status": "affected",
              "version": "e4165ae8304e5ea822fbe5909dd3be5445c058b7",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/v3d/v3d_submit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.9",
              "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": "6.1.176",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                },
                {
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                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
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                }
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/v3d: Reject empty multisync extension to prevent infinite loop\n\nv3d_get_extensions() walks a userspace-provided singly-linked list of\nioctl extensions without any bound on the chain length. A local user\ncan craft a self-referential extension (ext-\u003enext == \u0026ext) with zero\nin_sync_count and out_sync_count, which bypasses the existing duplicate-\nextension guard:\n\n    if (se-\u003ein_sync_count || se-\u003eout_sync_count)\n            return -EINVAL;\n\nThe guard never fires because v3d_get_multisync_post_deps() returns\nimmediately when count is zero, leaving both fields at zero on every\niteration. The result is an infinite loop in kernel context, blocking\nthe calling thread and pegging a CPU core indefinitely.\n\nFix this by rejecting a multisync extension where both in_sync_count\nand out_sync_count are zero in v3d_get_multisync_submit_deps(). An\nempty multisync carries no synchronization information and serves no\nuseful purpose, so returning -EINVAL for such an extension is the\ncorrect defense against this attack vector."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-19T12:00:14.686Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
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    "datePublished": "2026-06-08T15:50:45.305Z",
    "dateReserved": "2026-05-13T15:03:33.111Z",
    "dateUpdated": "2026-06-19T12:00:14.686Z",
    "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-24M2-RCHH-H2MX

CVE-2026-46314 (GCVE-0-2026-46314)

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