atm: update msg_namelen in vcc_recvmsg()

[ Upstream commit 9b3e617f3df53822345a8573b6d358f6b9e5ed87 ]

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/atm/common.c b/net/atm/common.c
index 0c0ad930a632f23e4c0661a20684c5d572e3dc15..f0a9b7eb37327a622bc94e40f14984d0b6f0a465 100644 (file)
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -520,6 +520,8 @@ 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;