From: Xin Long Date: Mon, 29 Oct 2018 15:10:29 +0000 (+0800) Subject: sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer X-Git-Tag: v4.19.6~73 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=cd947138e8c31e8cfcd489c12e9b97271beb6e79;p=platform%2Fkernel%2Flinux-rpi.git sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer commit df132eff463873e14e019a07f387b4d577d6d1f9 upstream. If a transport is removed by asconf but there still are some chunks with this transport queuing on out_chunk_list, later an use-after-free issue will be caused when accessing this transport from these chunks in sctp_outq_flush(). This is an old bug, we fix it by clearing the transport of these chunks in out_chunk_list when removing a transport in sctp_assoc_rm_peer(). Reported-by: syzbot+56a40ceee5fb35932f4d@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/sctp/associola.c b/net/sctp/associola.c index a827a1f..6a28b96 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -499,8 +499,9 @@ void sctp_assoc_set_primary(struct sctp_association *asoc, void sctp_assoc_rm_peer(struct sctp_association *asoc, struct sctp_transport *peer) { - struct list_head *pos; - struct sctp_transport *transport; + struct sctp_transport *transport; + struct list_head *pos; + struct sctp_chunk *ch; pr_debug("%s: association:%p addr:%pISpc\n", __func__, asoc, &peer->ipaddr.sa); @@ -564,7 +565,6 @@ void sctp_assoc_rm_peer(struct sctp_association *asoc, */ if (!list_empty(&peer->transmitted)) { struct sctp_transport *active = asoc->peer.active_path; - struct sctp_chunk *ch; /* Reset the transport of each chunk on this list */ list_for_each_entry(ch, &peer->transmitted, @@ -586,6 +586,10 @@ void sctp_assoc_rm_peer(struct sctp_association *asoc, sctp_transport_hold(active); } + list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) + if (ch->transport == peer) + ch->transport = NULL; + asoc->peer.transport_count--; sctp_transport_free(peer);