From 471e39df96b9a4c4ba88a2da9e25a126624d7a9c Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Wed, 24 Jun 2020 17:34:18 -0300 Subject: sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket If a socket is set ipv6only, it will still send IPv4 addresses in the INIT and INIT_ACK packets. This potentially misleads the peer into using them, which then would cause association termination. The fix is to not add IPv4 addresses to ipv6only sockets. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Corey Minyard Signed-off-by: Marcelo Ricardo Leitner Tested-by: Corey Minyard Signed-off-by: David S. Miller --- net/sctp/associola.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/sctp/associola.c') diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 72315137d7e7..8d735461fa19 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -1565,12 +1565,15 @@ void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len) int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, enum sctp_scope scope, gfp_t gfp) { + struct sock *sk = asoc->base.sk; int flags; /* Use scoping rules to determine the subset of addresses from * the endpoint. */ - flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; + flags = (PF_INET6 == sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; + if (!inet_v6_ipv6only(sk)) + flags |= SCTP_ADDR4_ALLOWED; if (asoc->peer.ipv4_address) flags |= SCTP_ADDR4_PEERSUPP; if (asoc->peer.ipv6_address) -- cgit v1.2.3