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CVE-2026-43278

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: dm: clear cloned request bio pointer when last clone bio completes Stale rq->bio values have been observed to cause double-initialization of cloned bios in request-based device-mapper targets, leading to use-after-free and double-free scenarios. One such case occurs when using dm-multipath on top of a PCIe NVMe namespace, where cloned request bios are freed during blk_complete_request(), but rq->bio is left intact. Subsequent clone teardown then attempts to free the same bios again via blk_rq_unprep_clone(). The resulting double-free path looks like: nvme_pci_complete_batch() nvme_complete_batch() blk_mq_end_request_batch() blk_complete_request() // called on a DM clone request bio_endio() // first free of all clone bios ... rq->end_io() // end_clone_request() dm_complete_request(tio->orig) dm_softirq_done() dm_done() dm_end_request() blk_rq_unprep_clone() // second free of clone bios Fix this by clearing the clone request's bio pointer when the last cloned bio completes, ensuring that later teardown paths do not attempt to free already-released bios.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-06 12:16:49.213000
Last modified
2026-10-19 20:18:12.583000
View original CVE JSON 
{
  "id": "CVE-2026-43278",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-05-06T12:16:49.213",
  "lastModified": "2026-10-19T20:18:12.583",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "affected": [
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      "affectedData": [
        {
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          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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          "programFiles": [
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
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            },
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              "lessThanOrEqual": "6.1.*",
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              "status": "unaffected"
            },
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            },
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              "version": "6.18.16",
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              "versionType": "semver",
              "status": "unaffected"
            },
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              "version": "6.19.6",
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            },
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              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
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        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
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          "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
      }
    ],
    "ssvcV203": [
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        "ssvcData": {
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          "id": "CVE-2026-43278",
          "options": [
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              "exploitation": "none"
            },
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          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
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  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
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          "value": "CWE-415"
        }
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    {
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          "negate": false,
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