SCTP: Add scope_id validation for link-local binds

SCTP currently permits users to bind to link-local addresses,
but doesn't verify that the scope id specified at bind matches
the interface that the address is configured on.  It was report
that this can hang a system.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 84cd53635fe8..2c29394fd92e 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -844,6 +844,10 @@ static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
                         dev = dev_get_by_index(addr->v6.sin6_scope_id);
                         if (!dev)
                                 return 0;
+                        if (!ipv6_chk_addr(&addr->v6.sin6_addr, dev, 0)) {
+                                dev_put(dev);
+                                return 0;
+                        }
                         dev_put(dev);
                 }
                 af = opt->pf->af;