atm: update msg_namelen in vcc_recvmsg()

The current code does not fill the msg_name member in case it is set.
It also does not set the msg_namelen member to 0 and therefore makes
net/socket.c leak the local, uninitialized sockaddr_storage variable
to userland -- 128 bytes of kernel stack memory.

Fix that by simply setting msg_namelen to 0 as obviously nobody cared
about vcc_recvmsg() not filling the msg_name in case it was set.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/atm/common.c b/net/atm/common.c
index 7b491006eaf4..737bef59ce89 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -531,6 +531,8 @@ int vcc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
         struct sk_buff *skb;
         int copied, error = -EINVAL;
 
+        msg->msg_namelen = 0;
+
         if (sock->state != SS_CONNECTED)
                 return -ENOTCONN;