atm: update msg_namelen in vcc_recvmsg()

commit 9b3e617f3df53822345a8573b6d358f6b9e5ed87 upstream.

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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/net/atm/common.c b/net/atm/common.c
index ec2cb8f3c8d9990a52c2a2a1d9008dbe5c2644d7..4ccc872209f0888c9a518e7d886a61b410d80b8d 100644 (file)
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -475,6 +475,8 @@ 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;
        if (flags & ~MSG_DONTWAIT)              /* only handle MSG_DONTWAIT */