[PATCH net] sctp: set sin_port for addr param when checking duplicate address

[Xin Long]

Commit b8607805dd15 ("sctp: not copying duplicate addrs to the assoc's
bind address list") tried to check for duplicate address before copying
to asoc's bind_addr list from global addr list.

But all the addrs' sin_ports in global addr list are 0 while the addrs'
sin_ports are bp->port in asoc's bind_addr list. It means even if it's
a duplicate address, af->cmp_addr will still return 0 as the their
sin_ports are different.

This patch is to fix it by setting the sin_port for addr param with
bp->port before comparing the addrs.

Fixes: b8607805dd15 ("sctp: not copying duplicate addrs to the assoc's bind 
address list")
Reported-by: Wei Chen <weic...@redhat.com>
Signed-off-by: Xin Long <lucien....@gmail.com>
---
 net/sctp/protocol.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 8227bbb..1b6d457 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -199,6 +199,7 @@ int sctp_copy_local_addr_list(struct net *net, struct 
sctp_bind_addr *bp,
                              sctp_scope_t scope, gfp_t gfp, int copy_flags)
 {
        struct sctp_sockaddr_entry *addr;
+       union sctp_addr laddr;
        int error = 0;
 
        rcu_read_lock();
@@ -220,7 +221,10 @@ int sctp_copy_local_addr_list(struct net *net, struct 
sctp_bind_addr *bp,
                     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
                        continue;
 
-               if (sctp_bind_addr_state(bp, &addr->a) != -1)
+               laddr = addr->a;
+               /* also works for setting ipv6 address port */
+               laddr.v4.sin_port = htons(bp->port);
+               if (sctp_bind_addr_state(bp, &laddr) != -1)
                        continue;
 
                error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
-- 
2.1.0