sctp: try harder to figure out address family when checking wildcards

sctp_is_any() function that is used to check for wildcard addresses
only looks at the address itself to determine the address family.
This function is used in the API to check the address passed in from
the user.  If the user simply zerroes out the sockaddr_storage and
pass that in, we'll end up failing.  So, let's try harder to determine
the address family by also checking the socket if it's possible.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
index f62bc2468935..6d5944a745d4 100644
--- a/net/sctp/bind_addr.c
+++ b/net/sctp/bind_addr.c
@@ -457,7 +457,7 @@ static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
 {
 	int error = 0;
 
-	if (sctp_is_any(addr)) {
+	if (sctp_is_any(NULL, addr)) {
 		error = sctp_copy_local_addr_list(dest, scope, gfp, flags);
 	} else if (sctp_in_scope(addr, scope)) {
 		/* Now that the address is in scope, check to see if
@@ -477,11 +477,21 @@ static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
 }
 
 /* Is this a wildcard address?  */
-int sctp_is_any(const union sctp_addr *addr)
+int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
 {
-	struct sctp_af *af = sctp_get_af_specific(addr->sa.sa_family);
+	unsigned short fam = 0;
+	struct sctp_af *af;
+
+	/* Try to get the right address family */
+	if (addr->sa.sa_family != AF_UNSPEC)
+		fam = addr->sa.sa_family;
+	else if (sk)
+		fam = sk->sk_family;
+
+	af = sctp_get_af_specific(fam);
 	if (!af)
 		return 0;
+
 	return af->is_any(addr);
 }