dm: clear cloned request bio pointer when last clone bio completes_CVE-2026-43278

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm: clear cloned request bio pointer when last clone bio completes\n\nStale rq->bio values have been observed to cause double-initialization of\ncloned bios in request-based device-mapper targets, leading to\nuse-after-free and double-free scenarios.\n\nOne such case occurs when using dm-multipath on top of a PCIe NVMe\nnamespace, where cloned request bios are freed during\nblk_complete_request(), but rq->bio is left intact. Subsequent clone\nteardown then attempts to free the same bios again via\nblk_rq_unprep_clone().\n\nThe resulting double-free path looks like:\n\n  nvme_pci_complete_batch()\n    nvme_complete_batch()\n      blk_mq_end_request_batch()\n        blk_complete_request()        // called on a DM clone request\n          bio_endio()                 // first free of all clone bios\n          ...\n        rq->end_io()                  // end_clone_request()\n          dm_complete_request(tio->orig)\n            dm_softirq_done()\n              dm_done()\n                dm_end_request()\n                  blk_rq_unprep_clone()  // second free of clone bios\n\nFix this by clearing the clone request's bio pointer when the last cloned\nbio completes, ensuring that later teardown paths do not attempt to free\nalready-released bios.",
    "published": "2026-05-06T11:29:00.193Z",
    "modified": "2026-05-08T12:41:43.313Z",
    "type": "cve",
    "title": "dm: clear cloned request bio pointer when last clone bio completes",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/8d9ddad561136f7e6a9346767bf97b4d79e38e67\nhttps://git.kernel.org/stable/c/7daf279c674d515fb22a727a7bbc92aeb35c5442\nhttps://git.kernel.org/stable/c/e2e738e8dfbbf83bd2bae0467ec4420cc52da42a\nhttps://git.kernel.org/stable/c/b1c1a2637ebd675aa2d71fee8c70da8791d73850\nhttps://git.kernel.org/stable/c/83d72091804600ead96dc9e9f518ea56cb4942f6\nhttps://git.kernel.org/stable/c/fb8a6c18fb9a6561f7a15b58b272442b77a242dd",
    "id": "CVE-2026-43278",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux ab3e1d3bbab9e973aeb4dd4603251578658a47ff\nLinux Linux ab3e1d3bbab9e973aeb4dd4603251578658a47ff\nLinux Linux ab3e1d3bbab9e973aeb4dd4603251578658a47ff\nLinux Linux ab3e1d3bbab9e973aeb4dd4603251578658a47ff\nLinux Linux ab3e1d3bbab9e973aeb4dd4603251578658a47ff\nLinux Linux ab3e1d3bbab9e973aeb4dd4603251578658a47ff\nLinux Linux 6.1",
    "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": {
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        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
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        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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            "baseScore": 0,
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "ab3e1d3bbab9e973aeb4dd4603251578658a47ff",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}