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, 1 insertions, 3 deletions

diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c
index 1865fdf5a5a5..1846c1fe0d06 100644
--- a/net/ieee802154/dgram.c
+++ b/net/ieee802154/dgram.c
@@ -291,9 +291,7 @@ static int dgram_recvmsg(struct kiocb *iocb, struct sock *sk,
         size_t copied = 0;
         int err = -EOPNOTSUPP;
         struct sk_buff *skb;
-        struct sockaddr_ieee802154 *saddr;
-
-        saddr = (struct sockaddr_ieee802154 *)msg->msg_name;
+        DECLARE_SOCKADDR(struct sockaddr_ieee802154 *, saddr, msg->msg_name);
 
         skb = skb_recv_datagram(sk, flags, noblock, &err);
         if (!skb)