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 ++++- net/sctp/bind_addr.c | 1 + net/sctp/protocol.c | 3 ++- 3 files changed, 7 insertions(+), 2 deletions(-) (limited to 'net') 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) diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c index 53bc61537f44..701c5a4e441d 100644 --- a/net/sctp/bind_addr.c +++ b/net/sctp/bind_addr.c @@ -461,6 +461,7 @@ static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest, * well as the remote peer. */ if ((((AF_INET == addr->sa.sa_family) && + (flags & SCTP_ADDR4_ALLOWED) && (flags & SCTP_ADDR4_PEERSUPP))) || (((AF_INET6 == addr->sa.sa_family) && (flags & SCTP_ADDR6_ALLOWED) && diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 092d1afdee0d..cde29f3c7fb3 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -148,7 +148,8 @@ int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp, * sock as well as the remote peer. */ if (addr->a.sa.sa_family == AF_INET && - !(copy_flags & SCTP_ADDR4_PEERSUPP)) + (!(copy_flags & SCTP_ADDR4_ALLOWED) || + !(copy_flags & SCTP_ADDR4_PEERSUPP))) continue; if (addr->a.sa.sa_family == AF_INET6 && (!(copy_flags & SCTP_ADDR6_ALLOWED) || -- cgit v1.2.3