In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sctp: discard the rest of the packet on a stale-cookie error<\/p>\n
When an association is in COOKIE-ECHOED state and the peer sends a
\nbundled [ERROR(Stale Cookie)][DATA] packet from one of its non-primary
\naddresses, processing the ERROR chunk takes the non-fatal stale-cookie
\nretry path sctp_sf_do_5_2_6_stale(), which queues
\nSCTP_CMD_DEL_NON_PRIMARY while keeping the association alive.
\nsctp_cmd_del_non_primary() removes every non-primary transport –
\nincluding the very transport this packet arrived on, which is still
\nreferenced by the receive lookup and shared by all chunks of the
\npacket via chunk->transport.<\/p>\n
sctp_assoc_rm_peer() does redirect asoc->peer.last_data_from away from
\nthe removed transport, but right afterwards the bundled DATA chunk
\nmakes sctp_assoc_bh_rcv() re-register
\nasoc->peer.last_data_from = chunk->transport unconditionally, undoing
\nthe redirection with the just-removed transport.<\/p>\n
Once the packet is done, the receive reference is dropped and the
\ntransport is RCU-freed, while the surviving association keeps the
\ndangling last_data_from. A later FWD-TSN (or the delayed SACK timer)
\nmakes sctp_gen_sack() dereference it (->param_flags and friends), and
\nsctp_make_sack()\/sctp_outq_select_transport() may write to the freed
\nobject and link it into the live transport list. This is a
\nuse-after-free triggerable by any malicious SCTP peer (or a local
\nunprivileged user acting as one) with no capabilities required:<\/p>\n
BUG: KASAN: slab-use-after-free in sctp_do_sm+0x498a\/0x5660
\n Read of size 4 at addr ffff88800e1e356c by task poc\/115
\n Call Trace: sctp_do_sm <- sctp_assoc_bh_rcv <- sctp_inq_push <-
\n sctp_rcv <- ip_protocol_deliver_rcu <- ip_rcv
\n Allocated: sctp_transport_new <- sctp_assoc_add_peer <-
\n sctp_process_init (INIT-ACK processing)
\n Freed: kfree <- sctp_transport_destroy_rcu transport: besides the last_data_from registration above,
\nsctp_cmd_setup_t2() and the sctp_make_*() reply builders would also
\ncopy that pointer into association-lifetime state that
\nsctp_assoc_rm_peer() has already sanitized. Let the peer retransmit
\nthem, in line with what sctp_inq_push() does for chunks whose
\ntransport was removed before processing.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sctp: discard the rest of the packet on a stale-cookie error<\/p>\n
When an association is in COOKIE-ECHOED state and the peer sends a
\nbu<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-41020","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/41020","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=41020"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41020"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}