{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-68227", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-16T13:41:40.257Z", "datePublished": "2025-12-16T13:57:20.027Z", "dateUpdated": "2026-05-11T21:49:17.263Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:49:17.263Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: Fix proto fallback detection with BPF\n\nThe sockmap feature allows bpf syscall from userspace, or based\non bpf sockops, replacing the sk_prot of sockets during protocol stack\nprocessing with sockmap's custom read/write interfaces.\n'''\ntcp_rcv_state_process()\n syn_recv_sock()/subflow_syn_recv_sock()\n tcp_init_transfer(BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB)\n bpf_skops_established <== sockops\n bpf_sock_map_update(sk) <== call bpf helper\n tcp_bpf_update_proto() <== update sk_prot\n'''\n\nWhen the server has MPTCP enabled but the client sends a TCP SYN\nwithout MPTCP, subflow_syn_recv_sock() performs a fallback on the\nsubflow, replacing the subflow sk's sk_prot with the native sk_prot.\n'''\nsubflow_syn_recv_sock()\n subflow_ulp_fallback()\n subflow_drop_ctx()\n mptcp_subflow_ops_undo_override()\n'''\n\nThen, this subflow can be normally used by sockmap, which replaces the\nnative sk_prot with sockmap's custom sk_prot. The issue occurs when the\nuser executes accept::mptcp_stream_accept::mptcp_fallback_tcp_ops().\nHere, it uses sk->sk_prot to compare with the native sk_prot, but this\nis incorrect when sockmap is used, as we may incorrectly set\nsk->sk_socket->ops.\n\nThis fix uses the more generic sk_family for the comparison instead.\n\nAdditionally, this also prevents a WARNING from occurring:\n\nresult from ./scripts/decode_stacktrace.sh:\n------------[ cut here ]------------\nWARNING: CPU: 0 PID: 337 at net/mptcp/protocol.c:68 mptcp_stream_accept \\\n(net/mptcp/protocol.c:4005)\nModules linked in:\n...\n\nPKRU: 55555554\nCall Trace:\n\ndo_accept (net/socket.c:1989)\n__sys_accept4 (net/socket.c:2028 net/socket.c:2057)\n__x64_sys_accept (net/socket.c:2067)\nx64_sys_call (arch/x86/entry/syscall_64.c:41)\ndo_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\nRIP: 0033:0x7f87ac92b83d\n\n---[ end trace 0000000000000000 ]---" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/mptcp/protocol.c" ], "versions": [ { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "92c4092fe012ecdfa5fb05d394f1c1d8f91ad81c", "status": "affected", "versionType": "git" }, { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "7ee8f015eb47907745e2070184a8ab1e442ac3c4", "status": "affected", "versionType": "git" }, { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "344974ea1a3ca30e4920687b0091bda4438cebdb", "status": "affected", "versionType": "git" }, { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "037cc50589643342d69185b663ecf9d26cce91e8", "status": "affected", "versionType": "git" }, { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "9b1980b6f23fa30bf12add19f37c7458625099eb", "status": "affected", "versionType": "git" }, { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "1a0d5c74af9b6ba9ffdf1172de5a1a6df5922a00", "status": "affected", "versionType": "git" }, { "version": "0b4f33def7bbde1ce2fea05f116639270e7acdc7", "lessThan": "c77b3b79a92e3345aa1ee296180d1af4e7031f8f", "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/mptcp/protocol.c" ], "versions": [ { "version": "5.7", "status": "affected" }, { "version": "0", "lessThan": "5.7", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.247", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.197", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.159", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.118", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.60", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.10", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "5.7", "versionEndExcluding": "5.10.247" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.15.197" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.1.159" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.6.118" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.12.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.17.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/92c4092fe012ecdfa5fb05d394f1c1d8f91ad81c" }, { "url": "https://git.kernel.org/stable/c/7ee8f015eb47907745e2070184a8ab1e442ac3c4" }, { "url": "https://git.kernel.org/stable/c/344974ea1a3ca30e4920687b0091bda4438cebdb" }, { "url": "https://git.kernel.org/stable/c/037cc50589643342d69185b663ecf9d26cce91e8" }, { "url": "https://git.kernel.org/stable/c/9b1980b6f23fa30bf12add19f37c7458625099eb" }, { "url": "https://git.kernel.org/stable/c/1a0d5c74af9b6ba9ffdf1172de5a1a6df5922a00" }, { "url": "https://git.kernel.org/stable/c/c77b3b79a92e3345aa1ee296180d1af4e7031f8f" } ], "title": "mptcp: Fix proto fallback detection with BPF", "x_generator": { "engine": "bippy-1.2.0" } } } }