net: add build-time checks for msg->msg_name size

This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg
handler msg_name and msg_namelen logic").

DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.

Signed-off-by: Steffen Hurrle <steffen@hurrle.net>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index eab17eb9ca1d..aab4948f0aff 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -608,7 +608,7 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 {
         struct sock *sk = sock->sk;
         struct tipc_port *tport = tipc_sk_port(sk);
-        struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
         int needs_conn;
         long timeo;
         int res = -EINVAL;
@@ -736,7 +736,7 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
 {
         struct sock *sk = sock->sk;
         struct tipc_port *tport = tipc_sk_port(sk);
-        struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
         int res = -EINVAL;
         long timeo;
 
@@ -906,7 +906,7 @@ static int auto_connect(struct socket *sock, struct tipc_msg *msg)
  */
 static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
 {
-        struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_tipc *, addr, m->msg_name);
 
         if (addr) {
                 addr->family = AF_TIPC;