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>
[PG: net/bluetooth/l2cap_sock.c --> net/bluetooth/l2cap.c in .34]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 0b6cf87d5eb009716c5110ae55a723acb5db7bb9..64ccd83d52a227339995c3d8ad3e451d8d92c800 100644 (file)
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1191,6 +1191,7 @@ 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);