{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-43455",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-01T14:12:56.010Z",
        "datePublished": "2026-05-08T14:22:19.375Z",
        "dateUpdated": "2026-05-11T22:24:55.256Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T22:24:55.256Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmctp: route: hold key->lock in mctp_flow_prepare_output()\n\nmctp_flow_prepare_output() checks key->dev and may call\nmctp_dev_set_key(), but it does not hold key->lock while doing so.\n\nmctp_dev_set_key() and mctp_dev_release_key() are annotated with\n__must_hold(&key->lock), so key->dev access is intended to be\nserialized by key->lock. The mctp_sendmsg() transmit path reaches\nmctp_flow_prepare_output() via mctp_local_output() -> mctp_dst_output()\nwithout holding key->lock, so the check-and-set sequence is racy.\n\nExample interleaving:\n\n  CPU0                                  CPU1\n  ----                                  ----\n  mctp_flow_prepare_output(key, devA)\n    if (!key->dev)  // sees NULL\n                                        mctp_flow_prepare_output(\n                                            key, devB)\n                                          if (!key->dev)  // still NULL\n                                          mctp_dev_set_key(devB, key)\n                                            mctp_dev_hold(devB)\n                                            key->dev = devB\n    mctp_dev_set_key(devA, key)\n      mctp_dev_hold(devA)\n      key->dev = devA   // overwrites devB\n\nNow both devA and devB references were acquired, but only the final\nkey->dev value is tracked for release. One reference can be lost,\ncausing a resource leak as mctp_dev_release_key() would only decrease\nthe reference on one dev.\n\nFix by taking key->lock around the key->dev check and\nmctp_dev_set_key() call."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/mctp/route.c"
                    ],
                    "versions": [
                        {
                            "version": "67737c457281dd199ceb9e31b6ba7efd3bfe566d",
                            "lessThan": "47893166bc5611ee9a20de6b8d2933b2320fb772",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "67737c457281dd199ceb9e31b6ba7efd3bfe566d",
                            "lessThan": "86f5334fcb48a5b611c33364ab52ca684d0f6d91",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "67737c457281dd199ceb9e31b6ba7efd3bfe566d",
                            "lessThan": "0695712f3a6f1a48915f95767cfb42077683dcdc",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "67737c457281dd199ceb9e31b6ba7efd3bfe566d",
                            "lessThan": "925a5ffd99cddd7a7e41d5ad120c7a2c6d50260f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "67737c457281dd199ceb9e31b6ba7efd3bfe566d",
                            "lessThan": "8d27d9b260dd19c1b519e1a13de6448f9984e30e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "67737c457281dd199ceb9e31b6ba7efd3bfe566d",
                            "lessThan": "7d86aa41c073c4e7eb75fd2e674f1fd8f289728a",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/mctp/route.c"
                    ],
                    "versions": [
                        {
                            "version": "5.16",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.16",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.167",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.130",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.78",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.19",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.9",
                            "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": "5.16",
                                    "versionEndExcluding": "6.1.167"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.16",
                                    "versionEndExcluding": "6.6.130"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.16",
                                    "versionEndExcluding": "6.12.78"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.16",
                                    "versionEndExcluding": "6.18.19"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.16",
                                    "versionEndExcluding": "6.19.9"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.16",
                                    "versionEndExcluding": "7.0"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/47893166bc5611ee9a20de6b8d2933b2320fb772"
                },
                {
                    "url": "https://git.kernel.org/stable/c/86f5334fcb48a5b611c33364ab52ca684d0f6d91"
                },
                {
                    "url": "https://git.kernel.org/stable/c/0695712f3a6f1a48915f95767cfb42077683dcdc"
                },
                {
                    "url": "https://git.kernel.org/stable/c/925a5ffd99cddd7a7e41d5ad120c7a2c6d50260f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8d27d9b260dd19c1b519e1a13de6448f9984e30e"
                },
                {
                    "url": "https://git.kernel.org/stable/c/7d86aa41c073c4e7eb75fd2e674f1fd8f289728a"
                }
            ],
            "title": "mctp: route: hold key->lock in mctp_flow_prepare_output()",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}