[097/126] Bluetooth: fix possible info leak in bt_sock_recvmsg()

Steven Rostedt
2013-05-07T04:38:16Z

[-- Attachment #1: 0097-Bluetooth-fix-possible-info-leak-in-bt_sock_recvmsg.patch --]
[-- Type: text/plain, Size: 1566 bytes --]

3.6.11.3 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Mathias Krause <minipli@googlemail.com>

[ Upstream commit 4683f42fde3977bdb4e8a09622788cc8b5313778 ]

In case the socket is already shutting down, bt_sock_recvmsg() returns
with 0 without updating msg_namelen leading to net/socket.c leaking the
local, uninitialized sockaddr_storage variable to userland -- 128 bytes
of kernel stack memory.

Fix this by moving the msg_namelen assignment in front of the shutdown
test.

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
net/bluetooth/af_bluetooth.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index f7db579..1801db0 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -229,6 +229,8 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
if (flags & (MSG_OOB))
return -EOPNOTSUPP;

+ msg->msg_namelen = 0;
+
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN)
@@ -236,8 +238,6 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
return err;
}

- msg->msg_namelen = 0;
-
copied = skb->len;
if (len < copied) {
msg->msg_flags |= MSG_TRUNC;
--
1.7.10.4