CVE-2026-52971 (GCVE-0-2026-52971)
Vulnerability from cvelistv5
Published
2026-06-24 16:28
Modified
2026-08-05 12:32
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: net: ena: PHC: Fix potential use-after-free in get_timestamp Move the phc->active check and resp pointer assignment to after acquiring the spinlock. Previously, phc->active was checked without holding the lock, and resp was cached from ena_dev->phc.virt_addr before the lock was acquired. If ena_com_phc_destroy() runs between the lockless active check and the lock acquisition, it sets active=false, releases the lock, frees the DMA memory, and sets virt_addr=NULL. The get_timestamp path would then read a NULL virt_addr and dereference it. With both the active check and the pointer read under the lock, destroy cannot free the memory while get_timestamp is using it.
References
Impacted products
Vendor Product Version
Linux Linux Version: e0ea34158ee8c4f7536cd781010339ff28c0d24c
Version: e0ea34158ee8c4f7536cd781010339ff28c0d24c
Version: e0ea34158ee8c4f7536cd781010339ff28c0d24c
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/amazon/ena/ena_com.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "e0ea34158ee8c4f7536cd781010339ff28c0d24c",
              "versionType": "git"
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              "status": "affected",
              "version": "e0ea34158ee8c4f7536cd781010339ff28c0d24c",
              "versionType": "git"
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          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/amazon/ena/ena_com.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "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": "6.18.33",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ena: PHC: Fix potential use-after-free in get_timestamp\n\nMove the phc-\u003eactive check and resp pointer assignment to after\nacquiring the spinlock. Previously, phc-\u003eactive was checked without\nholding the lock, and resp was cached from ena_dev-\u003ephc.virt_addr\nbefore the lock was acquired.\n\nIf ena_com_phc_destroy() runs between the lockless active check and\nthe lock acquisition, it sets active=false, releases the lock, frees\nthe DMA memory, and sets virt_addr=NULL. The get_timestamp path would\nthen read a NULL virt_addr and dereference it.\n\nWith both the active check and the pointer read under the lock,\ndestroy cannot free the memory while get_timestamp is using it."
        }
      ],
      "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 vulnerable ENA PHC timestamp path is reached through local PTP clock access such as opening `/dev/ptpN` and invoking `clock_gettime()`/PTP ioctls, not by remote network packets.\nAC:L - The bug is a retryable race between timestamp retrieval and ENA PHC destroy during reset/reinit, and repeated local timestamp calls can exercise the vulnerable window without special memory layout assumptions.\nPR:L - The generic PTP gettime path has no capability check; the attacker only needs local access to the PTP character device/file descriptor, which is a low-privilege local access condition.\nUI:N - No victim action is required once the attacker can access the local PTP clock interface and race it with reset/destruction activity.\nS:U - The vulnerability affects kernel memory within the same host kernel security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free of a coherent DMA response buffer whose contents are read back through timestamp retrieval, and under the required higher-severity rule UAF is treated as capable of high confidentiality impact.\nI:H - The stale response pointer is written through after free (`req_id` update) and may corrupt reused kernel/DMA memory, so under the UAF guidance this supports high integrity impact.\nA:H - The stale or NULL/freed pointer dereference can oops or panic the kernel during timestamp retrieval, causing high availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:32:13.881Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/95e8ae9af2a61b4e72f5c585bf4c7d8aaf2a2c98"
        },
        {
          "url": "https://git.kernel.org/stable/c/ca9ed40f28949353911dcb524ff8fff2f3409c97"
        },
        {
          "url": "https://git.kernel.org/stable/c/e42c755582f0960e684298762f0ab927b3778376"
        }
      ],
      "title": "net: ena: PHC: Fix potential use-after-free in get_timestamp",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-52971",
    "datePublished": "2026-06-24T16:28:49.637Z",
    "dateReserved": "2026-06-09T07:44:35.375Z",
    "dateUpdated": "2026-08-05T12:32:13.881Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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