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, 2 insertions, 2 deletions

diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
index e096025b477f..994e28bfb32e 100644
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -1707,7 +1707,7 @@ static int ipx_sendmsg(struct kiocb *iocb, struct socket *sock,
 {
         struct sock *sk = sock->sk;
         struct ipx_sock *ipxs = ipx_sk(sk);
-        struct sockaddr_ipx *usipx = (struct sockaddr_ipx *)msg->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_ipx *, usipx, msg->msg_name);
         struct sockaddr_ipx local_sipx;
         int rc = -EINVAL;
         int flags = msg->msg_flags;
@@ -1774,7 +1774,7 @@ static int ipx_recvmsg(struct kiocb *iocb, struct socket *sock,
 {
         struct sock *sk = sock->sk;
         struct ipx_sock *ipxs = ipx_sk(sk);
-        struct sockaddr_ipx *sipx = (struct sockaddr_ipx *)msg->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_ipx *, sipx, msg->msg_name);
         struct ipxhdr *ipx = NULL;
         struct sk_buff *skb;
         int copied, rc;