Bluetooth: A2MP: Fix not initializing all members

This fixes various places where a stack variable is used uninitialized.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

CVE-2020-12352
(cherry picked from commit eddb773 linux-next)
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>

net/bluetooth/a2mp.c

@@ -226,6 +226,9 @@ static int a2mp_discover_rsp(struct amp_mgr *mgr, struct sk_buff *skb,
 			struct a2mp_info_req req;
 
 			found = true;
+
+			memset(&req, 0, sizeof(req));
+
 			req.id = cl->id;
 			a2mp_send(mgr, A2MP_GETINFO_REQ, __next_ident(mgr),
 				  sizeof(req), &req);
@@ -305,6 +308,8 @@ static int a2mp_getinfo_req(struct amp_mgr *mgr, struct sk_buff *skb,
 	if (!hdev || hdev->dev_type != HCI_AMP) {
 		struct a2mp_info_rsp rsp;
 
+		memset(&rsp, 0, sizeof(rsp));
+
 		rsp.id = req->id;
 		rsp.status = A2MP_STATUS_INVALID_CTRL_ID;
 
@@ -348,6 +353,8 @@ static int a2mp_getinfo_rsp(struct amp_mgr *mgr, struct sk_buff *skb,
 	if (!ctrl)
 		return -ENOMEM;
 
+	memset(&req, 0, sizeof(req));
+
 	req.id = rsp->id;
 	a2mp_send(mgr, A2MP_GETAMPASSOC_REQ, __next_ident(mgr), sizeof(req),
 		  &req);
@@ -376,6 +383,8 @@ static int a2mp_getampassoc_req(struct amp_mgr *mgr, struct sk_buff *skb,
 		struct a2mp_amp_assoc_rsp rsp;
 		rsp.id = req->id;
 
+		memset(&rsp, 0, sizeof(rsp));
+
 		if (tmp) {
 			rsp.status = A2MP_STATUS_COLLISION_OCCURED;
 			amp_mgr_put(tmp);
@@ -464,7 +473,6 @@ static int a2mp_createphyslink_req(struct amp_mgr *mgr, struct sk_buff *skb,
 				   struct a2mp_cmd *hdr)
 {
 	struct a2mp_physlink_req *req = (void *) skb->data;
-
 	struct a2mp_physlink_rsp rsp;
 	struct hci_dev *hdev;
 	struct hci_conn *hcon;
@@ -475,6 +483,8 @@ static int a2mp_createphyslink_req(struct amp_mgr *mgr, struct sk_buff *skb,
 
 	BT_DBG("local_id %d, remote_id %d", req->local_id, req->remote_id);
 
+	memset(&rsp, 0, sizeof(rsp));
+
 	rsp.local_id = req->remote_id;
 	rsp.remote_id = req->local_id;
 
@@ -553,6 +563,8 @@ static int a2mp_discphyslink_req(struct amp_mgr *mgr, struct sk_buff *skb,
 
 	BT_DBG("local_id %d remote_id %d", req->local_id, req->remote_id);
 
+	memset(&rsp, 0, sizeof(rsp));
+
 	rsp.local_id = req->remote_id;
 	rsp.remote_id = req->local_id;
 	rsp.status = A2MP_STATUS_SUCCESS;
@@ -675,6 +687,8 @@ static int a2mp_chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 	if (err) {
 		struct a2mp_cmd_rej rej;
 
+		memset(&rej, 0, sizeof(rej));
+
 		rej.reason = cpu_to_le16(0);
 		hdr = (void *) skb->data;
 
@@ -898,6 +912,8 @@ void a2mp_send_getinfo_rsp(struct hci_dev *hdev)
 
 	BT_DBG("%s mgr %p", hdev->name, mgr);
 
+	memset(&rsp, 0, sizeof(rsp));
+
 	rsp.id = hdev->id;
 	rsp.status = A2MP_STATUS_INVALID_CTRL_ID;
 
@@ -995,6 +1011,8 @@ void a2mp_send_create_phy_link_rsp(struct hci_dev *hdev, u8 status)
 	if (!mgr)
 		return;
 
+	memset(&rsp, 0, sizeof(rsp));
+
 	hs_hcon = hci_conn_hash_lookup_state(hdev, AMP_LINK, BT_CONNECT);
 	if (!hs_hcon) {
 		rsp.status = A2MP_STATUS_UNABLE_START_LINK_CREATION;
@@ -1027,6 +1045,8 @@ void a2mp_discover_amp(struct l2cap_chan *chan)
 
 	mgr->bredr_chan = chan;
 
+	memset(&req, 0, sizeof(req));
+
 	req.mtu = cpu_to_le16(L2CAP_A2MP_DEFAULT_MTU);
 	req.ext_feat = 0;
 	a2mp_send(mgr, A2MP_DISCOVER_REQ, 1, sizeof(req), &req);