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>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 34a656d9..fdf5135 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2222,7 +2222,7 @@
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct sock *sk = sock->sk;
struct netlink_sock *nlk = nlk_sk(sk);
- struct sockaddr_nl *addr = msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
u32 dst_portid;
u32 dst_group;
struct sk_buff *skb;
@@ -2353,7 +2353,7 @@
err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
if (msg->msg_name) {
- struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
addr->nl_family = AF_NETLINK;
addr->nl_pad = 0;
addr->nl_pid = NETLINK_CB(skb).portid;