[v2.6.34-stable 022/213] rose: fix info leak via msg_name in rose_recvmsg()

[Paul Gortmaker]

From: Mathias Krause <minipli@xxxxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 4a184233f21645cf0b719366210ed445d1024d72 upstream.

The code in rose_recvmsg() does not initialize all of the members of
struct sockaddr_rose/full_sockaddr_rose when filling the sockaddr info.
Nor does it initialize the padding bytes of the structure inserted by
the compiler for alignment. This will lead to leaking uninitialized
kernel stack bytes in net/socket.c.

Fix the issue by initializing the memory used for sockaddr info with
memset(0).

Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 net/rose/af_rose.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 547e5cd6d375..11072546d7e9 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1277,6 +1277,7 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
 	skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 
 	if (srose != NULL) {
+		memset(srose, 0, msg->msg_namelen);
 		srose->srose_family = AF_ROSE;
 		srose->srose_addr   = rose->dest_addr;
 		srose->srose_call   = rose->dest_call;
-- 
1.8.5.2

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