irda: Fix missing msg_namelen update in irda_recvmsg_dgram()

commit 5ae94c0d2f0bed41d6718be743985d61b7f5c47d 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 irda_recvmsg_dgram() not filling the msg_name in case it was
set.

Cc: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[dannf: adjusted to apply to Debian's 2.6.32]
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
index 476b24ee7b712fa4c65b9fd160c2a63b2dfbe18a..bfb325de67cf1c647bbd691f9f59c25e9be58286 100644 (file)
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -1338,6 +1338,8 @@ static int irda_recvmsg_dgram(struct kiocb *iocb, struct socket *sock,
        if ((err = sock_error(sk)) < 0)
                return err;
 
+       msg->msg_namelen = 0;
+
        skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
                                flags & MSG_DONTWAIT, &err);
        if (!skb)