{"id":"CVE-2026-64564","summary":"sctp: don't free the ASCONF's own transport in DEL-IP processing","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: don't free the ASCONF's own transport in DEL-IP processing\n\nsctp_process_asconf() caches the transport the ASCONF chunk is processed\nagainst in asconf-\u003etransport (== chunk-\u003etransport, set once in sctp_rcv()).\nFor an ASCONF located through its Address Parameter by\n__sctp_rcv_asconf_lookup(), that cached transport corresponds to the\nAddress Parameter, which need not be the packet's source address.\n\nsctp_process_asconf_param() rejects a DEL-IP for the packet source address\n(ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf-\u003etransport.\nA single ASCONF can therefore carry, in order:\n\n    [Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0]\n\nwhere L differs from the source. The DEL-IP for L passes the D8 check and\ncalls sctp_assoc_rm_peer() on the transport that asconf-\u003etransport still\npoints at, freeing it (RCU-deferred). The following wildcard DEL-IP then\nreuses the now-dangling asconf-\u003etransport in sctp_assoc_set_primary() and\nsctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed\ntransport (-\u003eipaddr, -\u003estate) and plants the dangling pointer into\nasoc-\u003epeer.primary_path / active_path, and del_nonprimary_peers(), keeping\nonly the pointer that is no longer on the list, removes every real\ntransport, leaving the association with a transport_count of 0 and\nprimary_path/active_path pointing at freed memory.\n\nReject a DEL-IP that targets the transport the ASCONF is being processed\nagainst, mirroring the existing source-address guard, so the wildcard\nbranch can never reuse a freed transport.","modified":"2026-08-10T08:27:14.810375692Z","published":"2026-08-04T06:23:23.339Z","related":["openSUSE-SU-2026:11476-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64564.json"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/08/06/13"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/08/06/3"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/08/06/4"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/08/07/1"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/08/07/2"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/08/07/8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/74e8f3e7114f0e26d1b2c4c048044db9fcc27603"},{"type":"WEB","url":"https://git.kernel.org/stable/c/85aca407c560aba81b5ce9d3d6cf94c74077d19b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9b2854f86f0b56e9027d68e7a3fc909d1a9b566f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d136b29bf91dd8e3161281b87de597b7311d9462"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fedeb4468987bcaff85fe3061de5ae052d414740"},{"type":"WEB","url":"https://matrix.tencent.com/en/2026/08/06/sctphantom-CVE-2026-64564"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64564.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64564"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"42e30bf3463cd37d73839376662cb79b4d5c416c"},{"fixed":"fedeb4468987bcaff85fe3061de5ae052d414740"},{"fixed":"74e8f3e7114f0e26d1b2c4c048044db9fcc27603"},{"fixed":"85aca407c560aba81b5ce9d3d6cf94c74077d19b"},{"fixed":"d136b29bf91dd8e3161281b87de597b7311d9462"},{"fixed":"9b2854f86f0b56e9027d68e7a3fc909d1a9b566f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64564.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.25"},{"fixed":"6.6.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64564.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}