sctp: detect and prevent references to a freed transport in sendmsg

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "include/net/sctp/structs.h",
                        "net/sctp/socket.c",
                        "net/sctp/transport.c"
                    ],
                    "versions": [
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "547762250220325d350d0917a7231480e0f4142b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "3257386be6a7eb8a8bfc9cbfb746df4eb4fc70e8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "0f7df4899299ce4662e5f95badb9dbc57cc37fa5",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "7a63f4fb0efb4e69efd990cbb740a848679ec4b0",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "c6fefcb71d246baaf3bacdad1af7ff50ebcfe652",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "9e7c37fadb3be1fc33073fcf10aa96d166caa697",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "5bc83bdf5f5b8010d1ca5a4555537e62413ab4e2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "2e5068b7e0ae0a54f6cfd03a2f80977da657f1ee",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "df132eff463873e14e019a07f387b4d577d6d1f9",
                            "lessThan": "f1a69a940de58b16e8249dff26f74c8cc59b32be",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "26e51e5287eed4d96ea66a3da95429f42940f013",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8b97e045bd6d37f96f161e4d371ae174148e1587",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e044554e97e812eb257d073bcc130e0ea653858f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8376fdc999be008f0e9918db52f1ed8c08f5a1c9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "cd947138e8c31e8cfcd489c12e9b97271beb6e79",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "3.18.128",
                            "lessThan": "3.19",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "4.4.166",
                            "lessThan": "4.5",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "4.9.142",
                            "lessThan": "4.10",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "4.14.85",
                            "lessThan": "4.15",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "4.19.6",
                            "lessThan": "4.20",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "include/net/sctp/structs.h",
                        "net/sctp/socket.c",
                        "net/sctp/transport.c"
                    ],
                    "versions": [
                        {
                            "version": "4.20",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.20",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.4.293",
                            "lessThanOrEqual": "5.4.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.237",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.181",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.135",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.88",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.24",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.13.12",
                            "lessThanOrEqual": "6.13.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.14.3",
                            "lessThanOrEqual": "6.14.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.15",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }