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CVE-2026-72095 (GCVE-0-2026-72095)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-17 05:40
VLAI
Title
dma-fence: Make dma_fence_dedup_array() robust against 0-count input
Summary
In the Linux kernel, the following vulnerability has been resolved: dma-fence: Make dma_fence_dedup_array() robust against 0-count input dma_fence_dedup_array() returns 1 when called with num_fences == 0: the for-loop body never executes, j stays at 0, and the final `return ++j` yields 1. This contradicts both the kernel-doc ("Return: Number of unique fences remaining in the array") and the natural expectation that 0 input gives 0 output. The caller __dma_fence_unwrap_merge() bails out via the `if (count == 0 || count == 1)` fast path and so is save. But amdgpu_userq_wait_*() could reach the dedup call with a zero local count and dereference an uninitialized fence slot in the array. Make the contract match the documentation by returning 0 early. This also skips an unnecessary sort() call on an empty array.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 575ec9b0c2f11f40535ea737ed5a64792780d1ef , < 7aa8f3dba53422465dbe1be8dbb7240304462bb2 (git)
Affected: 575ec9b0c2f11f40535ea737ed5a64792780d1ef , < e2d9a2ea178a5da0b4a6693e8ebca5c7fc4d7051 (git)
Affected: 575ec9b0c2f11f40535ea737ed5a64792780d1ef , < 77a9298741f8f9e8b963c977f5582ab21c6d3427 (git)
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Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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          "product": "Linux",
          "programFiles": [
            "drivers/dma-buf/dma-fence-unwrap.c"
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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\ndma-fence: Make dma_fence_dedup_array() robust against 0-count input\n\ndma_fence_dedup_array() returns 1 when called with num_fences == 0:\nthe for-loop body never executes, j stays at 0, and the final\n`return ++j` yields 1. This contradicts both the kernel-doc (\"Return:\nNumber of unique fences remaining in the array\") and the natural\nexpectation that 0 input gives 0 output.\n\nThe caller __dma_fence_unwrap_merge() bails out via the\n`if (count == 0 || count == 1)` fast path and so is save.\n\nBut amdgpu_userq_wait_*() could reach the dedup call with a zero local\ncount and dereference an uninitialized fence slot in the array.\n\nMake the contract match the documentation by returning 0 early. This\nalso skips an unnecessary sort() call on an empty array."
        }
      ],
      "metrics": [
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          "cvssV3_1": {
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            "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 bug is reached only via the AMDGPU_USERQ_WAIT DRM ioctl on /dev/dri/renderD*, requiring local access to an AMD GPU render node; it is not reachable from network protocols or remote packet handling.\nAC:L - An attacker with render-node access can reliably trigger the bug by creating a userq, calling AMDGPU_USERQ_WAIT with num_fences\u003e0 and zero syncobj/BO handles so local num_fences stays 0 and dma_fence_dedup_array() incorrectly returns 1.\nPR:L - Exploitation requires only an authenticated DRM client on a render node (DRM_AUTH|DRM_RENDER_ALLOW), which unprivileged users commonly obtain via the render group on workstations, cloud GPU instances, and shared compute nodes.\nUI:N - No victim interaction is required; the attacker drives the vulnerable AMDGPU_USERQ_WAIT ioctl directly after creating their own user queue.\nS:U - Impact remains within the host kernel security domain (local privilege escalation/DoS on the GPU server); it does not cross VM, container, or IOMMU boundaries.\nC:H - When num_fences is 0 the dedup helper returns 1, causing iteration over uninitialized kmalloc slots whose stale contents are then dereferenced via to_amdgpu_userq_fence()/dma_fence_wait(), enabling kernel memory reads and pointer disclosure.\nI:H - The uninitialized fences[0] pointer is passed into dma_fence_enable_sw_signaling() and dma_fence_wait(), which invoke fence ops and locking on attacker-influenced addresses, creating a plausible path to control-flow hijacking via heap grooming.\nA:H - Dereferencing an uninitialized or attacker-influenced dma_fence pointer in kernel context can cause an oops, BUG, or panic, producing a repeatable local denial of service on affected AMDGPU userq systems."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:40:12.383Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/7aa8f3dba53422465dbe1be8dbb7240304462bb2"
        },
        {
          "url": "https://git.kernel.org/stable/c/e2d9a2ea178a5da0b4a6693e8ebca5c7fc4d7051"
        },
        {
          "url": "https://git.kernel.org/stable/c/77a9298741f8f9e8b963c977f5582ab21c6d3427"
        }
      ],
      "title": "dma-fence: Make dma_fence_dedup_array() robust against 0-count input",
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        "engine": "bippy-1.2.0"
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72095",
    "datePublished": "2026-08-15T05:52:41.470Z",
    "dateReserved": "2026-08-09T03:40:39.905Z",
    "dateUpdated": "2026-08-17T05:40:12.383Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-72095",
      "date": "2026-09-04",
      "epss": "0.00161",
      "percentile": "0.05621"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-72095\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:21:23.573\",\"lastModified\":\"2026-08-17T06:18:08.397\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\ndma-fence: Make dma_fence_dedup_array() robust against 0-count input\\n\\ndma_fence_dedup_array() returns 1 when called with num_fences == 0:\\nthe for-loop body never executes, j stays at 0, and the final\\n`return ++j` yields 1. This contradicts both the kernel-doc (\\\"Return:\\nNumber of unique fences remaining in the array\\\") and the natural\\nexpectation that 0 input gives 0 output.\\n\\nThe caller __dma_fence_unwrap_merge() bails out via the\\n`if (count == 0 || count == 1)` fast path and so is save.\\n\\nBut amdgpu_userq_wait_*() could reach the dedup call with a zero local\\ncount and dereference an uninitialized fence slot in the array.\\n\\nMake the contract match the documentation by returning 0 early. This\\nalso skips an unnecessary sort() call on an empty array.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/dma-buf/dma-fence-unwrap.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"575ec9b0c2f11f40535ea737ed5a64792780d1ef\",\"lessThan\":\"7aa8f3dba53422465dbe1be8dbb7240304462bb2\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"575ec9b0c2f11f40535ea737ed5a64792780d1ef\",\"lessThan\":\"e2d9a2ea178a5da0b4a6693e8ebca5c7fc4d7051\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"575ec9b0c2f11f40535ea737ed5a64792780d1ef\",\"lessThan\":\"77a9298741f8f9e8b963c977f5582ab21c6d3427\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/dma-buf/dma-fence-unwrap.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.16\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.16\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/77a9298741f8f9e8b963c977f5582ab21c6d3427\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7aa8f3dba53422465dbe1be8dbb7240304462bb2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e2d9a2ea178a5da0b4a6693e8ebca5c7fc4d7051\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-17T21:48:33+00:00",
      "cve": "CVE-2026-72095",
      "id": "CVE-2026-72095",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: dma-fence: Make dma_fence_dedup_array() robust against 0-count input",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72095.json",
      "version": "3"
    }
  }
}



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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.

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  • 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.
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  • 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.


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