Bluetooth: L2CAP - Fix info leak via getsockname()

commit 792039c73cf176c8e39a6e8beef2c94ff46522ed upstream.

The L2CAP code fails to initialize the l2_bdaddr_type member of struct
sockaddr_l2 and the padding byte added for alignment. It that for leaks
two bytes kernel stack via the getsockname() syscall. Add an explicit
memset(0) before filling the structure to avoid the info leak.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 2.6.32: adjust filename]
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 71120ee8511e8e07277220dbae719b54840a4549..1c20bd98d16dddd8dc3d8a10dd9dbb779fcc6913 100644 (file)
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1184,6 +1184,7 @@ static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, int *l
 
        BT_DBG("sock %p, sk %p", sock, sk);
 
+       memset(la, 0, sizeof(struct sockaddr_l2));
        addr->sa_family = AF_BLUETOOTH;
        *len = sizeof(struct sockaddr_l2);