Commit 4683f42f authored Apr 07, 2013 by Mathias Krause Committed by David S. Miller Apr 07, 2013

Bluetooth: fix possible info leak in bt_sock_recvmsg()



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>

parent ef3313e8

net/bluetooth/af_bluetooth.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -230,6 +230,8 @@ 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)
		@@ -237,8 +239,6 @@ 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;