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

Vulnerability from cvelistv5 – Published: 2026-06-08 15:50 – Updated: 2026-06-08 15:50
VLAI
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
References
Impacted products
Vendor Product Version
Linux Linux Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < 4fa42a249e8cd6ed17aea04e5695b6e9001f2433 (git)
Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < 9c5164781cb388d219d8f49fa0f0b04cf86ad544 (git)
Affected: e4165ae8304e5ea822fbe5909dd3be5445c058b7 , < fb44d589bf3148e13452185a6e772a7efbf2d684 (git)
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Linux Linux Affected: 5.16
Unaffected: 0 , < 5.16 (semver)
Unaffected: 6.18.33 , ≤ 6.18.* (semver)
Unaffected: 7.0.9 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/v3d/v3d_submit.c"
          ],
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          "vendor": "Linux",
          "versions": [
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              "versionType": "git"
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              "versionType": "git"
            }
          ]
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "0",
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              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
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      "cpeApplicability": [
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                  "versionStartIncluding": "5.16",
                  "vulnerable": true
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                  "vulnerable": true
                }
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              "negate": false,
              "operator": "OR"
            }
          ]
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      ],
      "descriptions": [
        {
          "lang": "en",
          "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": "2026-06-08T15:50:45.305Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433"
        },
        {
          "url": "https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544"
        },
        {
          "url": "https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684"
        }
      ],
      "title": "drm/v3d: Reject empty multisync extension to prevent infinite loop",
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        "engine": "bippy-1.2.0"
      }
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46314",
    "datePublished": "2026-06-08T15:50:45.305Z",
    "dateReserved": "2026-05-13T15:03:33.111Z",
    "dateUpdated": "2026-06-08T15:50:45.305Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-46314",
      "date": "2026-06-09",
      "epss": "0.00017",
      "percentile": "0.04231"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-46314\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-06-08T17:16:50.430\",\"lastModified\":\"2026-06-08T17:16:50.430\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"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.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.