From: Qiujun Huang <hqjagain@xxxxxxxxx> Date: Fri, 27 Mar 2020 11:07:51 +0800 > We should iterate over the datamsgs to move > all chunks(skbs) to newsk. > > The following case cause the bug: > for the trouble SKB, it was in outq->transmitted list > > sctp_outq_sack > sctp_check_transmitted > SKB was moved to outq->sacked list > then throw away the sack queue > SKB was deleted from outq->sacked > (but it was held by datamsg at sctp_datamsg_to_asoc > So, sctp_wfree was not called here) > > then migrate happened > > sctp_for_each_tx_datachunk( > sctp_clear_owner_w); > sctp_assoc_migrate(); > sctp_for_each_tx_datachunk( > sctp_set_owner_w); > SKB was not in the outq, and was not changed to newsk > > finally > > __sctp_outq_teardown > sctp_chunk_put (for another skb) > sctp_datamsg_put > __kfree_skb(msg->frag_list) > sctp_wfree (for SKB) > SKB->sk was still oldsk (skb->sk != asoc->base.sk). > > Reported-and-tested-by: syzbot+cea71eec5d6de256d54d@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Qiujun Huang <hqjagain@xxxxxxxxx> Applied and queued up for -stable, thanks.
