{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-80849",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-26T14:34:25.797Z",
        "datePublished": "2026-09-04T15:54:59.412Z",
        "dateUpdated": "2026-10-19T08:44:43.405Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:44:43.405Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-ao: fix use-after-free of current_key on reconnect to another peer\n\ntcp_inbound_ao_hash() is called before bh_lock_sock_nested() is taken,\nwith only rcu_read_lock() held. On the fast path for established\nsockets, if the rnext_keyid sent by the peer differs from\ncurrent_key->sndid, the key the peer asked for is looked up and stored\nin current_key. The lookup is inside the RCU read side, but current_key\noutlives it.\n\nWhen the socket is disconnected and connect() is called again for\nanother peer, tcp_ao_connect_init() unlinks every key that does not\nmatch the new peer and frees it with call_rcu(). If current_key points\nat such a key, it is cleared to NULL.\n\nThe fast path reads sk_state only once on entry, so a softirq that got\ninto it while the socket was still established can update current_key\nafter that loop has already run. The update is inside the RCU read side,\nso it comes before the call_rcu() callback, and once the callback frees\nthe key, current_key is left pointing at freed memory.\n\nThe next transmission picks that pointer up in tcp_get_current_key().\ntcp_ao_transmit_skb() then reads the traffic key from the freed object,\nwhich is the use-after-free.\n\nWait for one grace period before unlinking, and only if a key is going\nto be removed. By the time tcp_connect() runs the socket is already in\nTCP_SYN_SENT, and TCP_AO_ESTABLISHED does not contain TCPF_SYN_SENT, so\na softirq entering after the wait cannot reach the fast path, and the\nones already in it have finished. The existing NULL handling in the loop\nis then enough."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/tcp_ao.c"
                    ],
                    "versions": [
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "84a93b4e012587d0a4a84ffb23ec6da18e9d85f9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "73fde8fe4469f4ed8f0afcc0b9d6413002a9e6b3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "e54ad693eddb40c595add013f545354c538e325b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "2857dcbd03cf3354af0fba1b65c6a260fb43811a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0a3a809089eb1d4a0a2fd0c16b520d603988c859",
                            "lessThan": "da4471557f279d0f56605158a625bb6e49ef7d41",
                            "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/ipv4/tcp_ao.c"
                    ],
                    "versions": [
                        {
                            "version": "6.7",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.7",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.108",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.49",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.13",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.3",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "6.7",
                                    "versionEndExcluding": "6.12.108"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.18.49"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "7.1.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "7.2.3"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/84a93b4e012587d0a4a84ffb23ec6da18e9d85f9"
                },
                {
                    "url": "https://git.kernel.org/stable/c/73fde8fe4469f4ed8f0afcc0b9d6413002a9e6b3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e54ad693eddb40c595add013f545354c538e325b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2857dcbd03cf3354af0fba1b65c6a260fb43811a"
                },
                {
                    "url": "https://git.kernel.org/stable/c/da4471557f279d0f56605158a625bb6e49ef7d41"
                }
            ],
            "title": "net/tcp-ao: fix use-after-free of current_key on reconnect to another peer",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}