{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-43271",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-01T14:12:55.998Z",
        "datePublished": "2026-05-06T11:28:55.507Z",
        "dateUpdated": "2026-05-11T22:21:19.841Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T22:21:19.841Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd-cluster: fix NULL pointer dereference in process_metadata_update\n\nThe function process_metadata_update() blindly dereferences the 'thread'\npointer (acquired via rcu_dereference_protected) within the wait_event()\nmacro.\n\nWhile the code comment states \"daemon thread must exist\", there is a valid\nrace condition window during the MD array startup sequence (md_run):\n\n1. bitmap_load() is called, which invokes md_cluster_ops->join().\n2. join() starts the \"cluster_recv\" thread (recv_daemon).\n3. At this point, recv_daemon is active and processing messages.\n4. However, mddev->thread (the main MD thread) is not initialized until\n   later in md_run().\n\nIf a METADATA_UPDATED message is received from a remote node during this\nspecific window, process_metadata_update() will be called while\nmddev->thread is still NULL, leading to a kernel panic.\n\nTo fix this, we must validate the 'thread' pointer. If it is NULL, we\nrelease the held lock (no_new_dev_lockres) and return early, safely\nignoring the update request as the array is not yet fully ready to\nprocess it."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/md/md-cluster.c"
                    ],
                    "versions": [
                        {
                            "version": "0ba959774e93911caff596de6391f085fb640ac4",
                            "lessThan": "a61c1bc84c4a0f1e7c2fe55b0f43d7d94af4adf1",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ba959774e93911caff596de6391f085fb640ac4",
                            "lessThan": "dec123825c1ed74d98fd5fc7571a851dea4f46ff",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ba959774e93911caff596de6391f085fb640ac4",
                            "lessThan": "721599e837d3f4c0e6cc14da059612c017b6d3ec",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ba959774e93911caff596de6391f085fb640ac4",
                            "lessThan": "dceb5a843910004cb118148e267036104fc3ee43",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ba959774e93911caff596de6391f085fb640ac4",
                            "lessThan": "f150e753cb8dd756085f46e86f2c35ce472e0a3c",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/md/md-cluster.c"
                    ],
                    "versions": [
                        {
                            "version": "4.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.128",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.75",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.16",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.6",
                            "lessThanOrEqual": "6.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.6.128"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.12.75"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.18.16"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.19.6"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "7.0"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a61c1bc84c4a0f1e7c2fe55b0f43d7d94af4adf1"
                },
                {
                    "url": "https://git.kernel.org/stable/c/dec123825c1ed74d98fd5fc7571a851dea4f46ff"
                },
                {
                    "url": "https://git.kernel.org/stable/c/721599e837d3f4c0e6cc14da059612c017b6d3ec"
                },
                {
                    "url": "https://git.kernel.org/stable/c/dceb5a843910004cb118148e267036104fc3ee43"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f150e753cb8dd756085f46e86f2c35ce472e0a3c"
                }
            ],
            "title": "md-cluster: fix NULL pointer dereference in process_metadata_update",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}