[PATCH] can: test size of struct sockaddr

[Kurt Van Dijck <kurt.van.dijck-/BeEPy95v10@public.gmane.org>]

I think this patch makes the CAN socket code comform to the
manpages of sendmsg & recvmsg.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck-/BeEPy95v10@public.gmane.org>
---
 net/can/bcm.c |    6 +++++-
 net/can/raw.c |    6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 6faa825..dc0d5d6 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -1256,6 +1256,9 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
 		struct sockaddr_can *addr =
 			(struct sockaddr_can *)msg->msg_name;
 
+		if (msg->msg_namelen < sizeof(*addr))
+			return -EINVAL;
+
 		if (addr->can_family != AF_CAN)
 			return -EINVAL;
 
@@ -1557,8 +1560,9 @@ static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
 	sock_recv_ts_and_drops(msg, sk, skb);
 
 	if (msg->msg_name) {
+		memcpy(msg->msg_name, skb->cb, MIN(msg->msg_namelen,
+					sizeof(struct sockaddr_can)));
 		msg->msg_namelen = sizeof(struct sockaddr_can);
-		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 	}
 
 	skb_free_datagram(sk, skb);
diff --git a/net/can/raw.c b/net/can/raw.c
index e88f610..e68a6d3 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -649,6 +649,9 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 		struct sockaddr_can *addr =
 			(struct sockaddr_can *)msg->msg_name;
 
+		if (msg->msg_namelen < sizeof(*addr))
+			return -EINVAL;
+
 		if (addr->can_family != AF_CAN)
 			return -EINVAL;
 
@@ -727,8 +730,9 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 	sock_recv_ts_and_drops(msg, sk, skb);
 
 	if (msg->msg_name) {
+		memcpy(msg->msg_name, skb->cb, MIN(msg->msg_namelen,
+					sizeof(struct sockaddr_can)));
 		msg->msg_namelen = sizeof(struct sockaddr_can);
-		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 	}
 
 	/* assign the flags that have been recorded in raw_rcv() */