In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sctp: don’t free the ASCONF’s own transport in DEL-IP processing<\/p>\n
sctp_process_asconf() caches the transport the ASCONF chunk is processed
\nagainst in asconf->transport (== chunk->transport, 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.<\/p>\n
sctp_process_asconf_param() rejects a DEL-IP for the packet source address
\n(ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport.
\nA single ASCONF can therefore carry, in order:<\/p>\n
[Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0]<\/p>\n
where 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->transport still
\npoints at, freeing it (RCU-deferred). The following wildcard DEL-IP then
\nreuses the now-dangling asconf->transport in sctp_assoc_set_primary() and
\nsctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed
\ntransport (->ipaddr, ->state) and plants the dangling pointer into
\nasoc->peer.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.<\/p>\n
Reject 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.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sctp: don’t free the ASCONF’s own transport in DEL-IP processing<\/p>\n
sctp_process_asconf() caches the transport the ASCONF chunk is pr<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-4486","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/4486","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4486"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4486"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4486"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}