This is a note to let you know that I've just added the patch titled netfilter: conntrack: don't refresh sctp entries in closed state to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: netfilter-conntrack-don-t-refresh-sctp-entries-in-cl.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 09dd239fe738337054d59f7b2f1109221aa18ae1 Author: Florian Westphal <fw@xxxxxxxxx> Date: Fri Jan 28 13:13:32 2022 +0100 netfilter: conntrack: don't refresh sctp entries in closed state [ Upstream commit 77b337196a9d87f3d6bb9b07c0436ecafbffda1e ] Vivek Thrivikraman reported: An SCTP server application which is accessed continuously by client application. When the session disconnects the client retries to establish a connection. After restart of SCTP server application the session is not established because of stale conntrack entry with connection state CLOSED as below. (removing this entry manually established new connection): sctp 9 CLOSED src=10.141.189.233 [..] [ASSURED] Just skip timeout update of closed entries, we don't want them to stay around forever. Reported-and-tested-by: Vivek Thrivikraman <vivek.thrivikraman@xxxxxxxx> Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1579 Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 810cca24b3990..7626f3e1c70a7 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -489,6 +489,15 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct, pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir); ct->proto.sctp.vtag[!dir] = ih->init_tag; + + /* don't renew timeout on init retransmit so + * port reuse by client or NAT middlebox cannot + * keep entry alive indefinitely (incl. nat info). + */ + if (new_state == SCTP_CONNTRACK_CLOSED && + old_state == SCTP_CONNTRACK_CLOSED && + nf_ct_is_confirmed(ct)) + ignore = true; } ct->proto.sctp.state = new_state;