From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Date: Wed, 24 Jun 2020 20:34:18 +0000 Subject: [PATCH net] sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket Message-Id: <991916791cdcc37456ccb061779d485063b97129.1593030427.git.marcelo.leitner@gmail.com> List-Id: References: <20200623160417.12418-1-minyard@acm.org> In-Reply-To: <20200623160417.12418-1-minyard@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Cc: Xin Long , Michael Tuexen , Yasevich , Neil Horman , linux-sctp@vger.kernel.org, linux-kernel@vger.kernel.org, Corey Minyard 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 --- include/net/sctp/constants.h | 8 +++++--- net/sctp/associola.c | 5 ++++- net/sctp/bind_addr.c | 1 + net/sctp/protocol.c | 3 ++- 4 files changed, 12 insertions(+), 5 deletions(-) diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h index 15b4d9aec7ff278e67a7183f10c14be237227d6b..122d9e2d8dfde33b787d575fc42d454732550698 100644 --- a/include/net/sctp/constants.h +++ b/include/net/sctp/constants.h @@ -353,11 +353,13 @@ enum { ipv4_is_anycast_6to4(a)) /* Flags used for the bind address copy functions. */ -#define SCTP_ADDR6_ALLOWED 0x00000001 /* IPv6 address is allowed by +#define SCTP_ADDR4_ALLOWED 0x00000001 /* IPv4 address is allowed by local sock family */ -#define SCTP_ADDR4_PEERSUPP 0x00000002 /* IPv4 address is supported by +#define SCTP_ADDR6_ALLOWED 0x00000002 /* IPv6 address is allowed by + local sock family */ +#define SCTP_ADDR4_PEERSUPP 0x00000004 /* IPv4 address is supported by peer */ -#define SCTP_ADDR6_PEERSUPP 0x00000004 /* IPv6 address is supported by +#define SCTP_ADDR6_PEERSUPP 0x00000008 /* IPv6 address is supported by peer */ /* Reasons to retransmit. */ diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 72315137d7e7f20d5182291ef4b01102f030078b..8d735461fa196567ab19c583703aad098ef8e240 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 53bc61537f44f4e766c417fcef72234df52ecd04..701c5a4e441d9c248df9472f22db5b78987f9e44 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 092d1afdee0d23cd974210839310fbf406dd443f..cde29f3c7fb3c40ee117636fa3b4b7f0a03e4fba 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) || -- 2.25.4