lib: test_hmm: evict device pages on file close to avoid use-after-free_CVE-2026-46280

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nlib: test_hmm: evict device pages on file close to avoid use-after-free\n\nPatch series \"Minor hmm_test fixes and cleanups\".\n\nTwo bugfixes a cleanup for the HMM kernel selftests.  These were mostly\nreported by Zenghui Yu with special thanks to Lorenzo for analysing and\npointing out the problems.\n\n\nThis patch (of 3):\n\nWhen dmirror_fops_release() is called it frees the dmirror struct but\ndoesn't migrate device private pages back to system memory first.  This\nleaves those pages with a dangling zone_device_data pointer to the freed\ndmirror.\n\nIf a subsequent fault occurs on those pages (eg.  during coredump) the\ndmirror_devmem_fault() callback dereferences the stale pointer causing a\nkernel panic.  This was reported [1] when running mm/ksft_hmm.sh on arm64,\nwhere a test failure triggered SIGABRT and the resulting coredump walked\nthe VMAs faulting in the stale device private pages.\n\nFix this by calling dmirror_device_evict_chunk() for each devmem chunk in\ndmirror_fops_release() to migrate all device private pages back to system\nmemory before freeing the dmirror struct.  The function is moved earlier\nin the file to avoid a forward declaration.",
    "published": "2026-06-08T15:41:23.095Z",
    "modified": "2026-06-14T04:29:58.926Z",
    "type": "cve",
    "title": "lib: test_hmm: evict device pages on file close to avoid use-after-free",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/bf477abd448c76bb8ea51c9b4f63a3a17c4b6239\nhttps://git.kernel.org/stable/c/5846715b6382dd4c6a69b35a56ca6115d33bc2a0\nhttps://git.kernel.org/stable/c/38f113f81d3f0adc658a4475dd3ecaec985e21d3\nhttps://git.kernel.org/stable/c/9de1eb0aac2862d6144b8db0ec1388e79f8bc3e1\nhttps://git.kernel.org/stable/c/744dd97752ef1076a8d8672bb0d8aa2c7abc1144",
    "id": "CVE-2026-46280",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux b2ef9f5a5cb37643ca5def3516c546457074b882\nLinux Linux b2ef9f5a5cb37643ca5def3516c546457074b882\nLinux Linux b2ef9f5a5cb37643ca5def3516c546457074b882\nLinux Linux b2ef9f5a5cb37643ca5def3516c546457074b882\nLinux Linux b2ef9f5a5cb37643ca5def3516c546457074b882\nLinux Linux 5.8",
    "sourceHref": "",
    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
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            "privilegesRequired": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "b2ef9f5a5cb37643ca5def3516c546457074b882",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
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    "ai_version": "",
    "ai_score": 0
}