net: sctp: rfc4443: do not report ICMP redirects to user space
Adapt the same behaviour for SCTP as present in TCP for ICMP redirect
messages. For IPv6, RFC4443, section 2.4. says:
...
(e) An ICMPv6 error message MUST NOT be originated as a result of
receiving the following:
...
(e.2) An ICMPv6 redirect message [IPv6-DISC].
...
Therefore, do not report an error to user space, just invoke dst's redirect
callback and leave, same for IPv4 as done in TCP as well. The implication
w/o having this patch could be that the reception of such packets would
generate a poll notification and in worst case it could even tear down the
whole connection. Therefore, stop updating sk_err on redirects.
Reported-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Suggested-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 4f52e2c..e7b2d4f 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -183,7 +183,7 @@
break;
case NDISC_REDIRECT:
sctp_icmp_redirect(sk, transport, skb);
- break;
+ goto out_unlock;
default:
break;
}