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Xin Long authored
Now sctp stream reconf will process a request again even if it's seqno is less than asoc->strreset_inseq. If one request has been done successfully and some data chunks have been accepted and then a duplicated strreset out request comes, the streamin's ssn will be cleared. It will cause that stream will never receive chunks any more because of unsynchronized ssn. It allows a replay attack. A similar issue also exists when processing addstrm out requests. It will cause more extra streams being added. This patch is to fix it by saving the last 2 results into asoc. When a duplicated strreset out or addstrm out request is received, reply it with bad seqno if it's seqno < asoc->strreset_inseq - 2, and reply it with the result saved in asoc if it's seqno >= asoc->strreset_inseq - 2. Note that it saves last 2 results instead of only last 1 result, because two requests can be sent together in one chunk. And note that when receiving a duplicated request, the receiver side will still reply it even if the peer has received the response. It's safe, As the response will be dropped by the peer. Signed-off-by:
Xin Long <lucien.xin@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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