In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sctp: keep chunk->transport in step with the list it is queued on<\/p>\n
__sctp_outq_flush_rtx() moves a gap-acked chunk onto another transport’s
\ntransmitted list without updating chunk->transport:<\/p>\n
\tif (chunk->tsn_gap_acked) {
\n\t\tlist_move_tail(&chunk->transmitted_list,
\n\t\t\t &transport->transmitted);
\n\t\tcontinue;
\n\t}<\/p>\n
The chunk then sits on a live transport’s list while chunk->transport still
\nnames a different one. If that transport is removed – sctp_assoc_rm_peer()
\nfrom an ASCONF Delete-IP – sctp_transport_free() RCU-frees it and the chunk
\nis left with a dangling pointer. sctp_assoc_rm_peer() scrubs
\npeer->transmitted and asoc->outqueue.out_chunk_list, but the chunk is on
\nneither.<\/p>\n
The pointer is not followed while tsn_gap_acked is set. A SACK that
\nreneges on the TSN clears the flag, and the next SACK reaches<\/p>\n
\ttchunk->transport->flight_size -= sctp_data_size(tchunk);<\/p>\n
inside the freed transport. KASAN reports a slab-use-after-free read in
\nsctp_check_transmitted(), freed from sctp_assoc_rm_peer(). Both the
\nremoval and the SACKs come from the association peer.<\/p>\n
Set chunk->transport at the move. The ordinary resend path needs nothing:
\nit reaches its list_move_tail() only after sctp_packet_append_chunk()
\nreturned SCTP_XMIT_OK, and __sctp_packet_append_chunk() has rebound the
\nchunk by then.<\/p>\n
Discovered by XBOW, triaged by Baul Lee <\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sctp: keep chunk->transport in step with the list it is queued on<\/p>\n
__sctp_outq_flush_rtx() moves a gap-acked chunk onto another tra<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-11199","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/11199","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=11199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11199"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}