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, 2 deletions

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index d080eb4b0d29..c2cca2ee6aef 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1051,7 +1051,7 @@ static int rose_sendmsg(struct kiocb *iocb, struct socket *sock,
 {
         struct sock *sk = sock->sk;
         struct rose_sock *rose = rose_sk(sk);
-        struct sockaddr_rose *usrose = (struct sockaddr_rose *)msg->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_rose *, usrose, msg->msg_name);
         int err;
         struct full_sockaddr_rose srose;
         struct sk_buff *skb;
@@ -1253,7 +1253,8 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
 
         if (msg->msg_name) {
                 struct sockaddr_rose *srose;
-                struct full_sockaddr_rose *full_srose = msg->msg_name;
+                DECLARE_SOCKADDR(struct full_sockaddr_rose *, full_srose,
+                                 msg->msg_name);
 
                 memset(msg->msg_name, 0, sizeof(struct full_sockaddr_rose));
                 srose = msg->msg_name;