Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Sonny Sasaka <sonnysasaka@chromium.org>
To:     linux-bluetooth@vger.kernel.org
Cc:     Sonny Sasaka <sonnysasaka@chromium.org>
Subject: [PATCH] Bluetooth: Fix auto-creation of hci_conn at Conn Complete event
Date:   Fri, 14 Aug 2020 12:04:06 -0700
Message-Id: <20200814190406.361415-1-sonnysasaka@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Currently the code auto-creates hci_conn only if the remote address has
been discovered before. This may not be the case. For example, the
remote device may trigger connection after reboot at already-paired
state so there is no inquiry result found, but it is still correct to
create the hci_conn when Connection Complete event is received.

A better guard is to check against bredr allowlist. Devices in the
allowlist have been given permission to auto-connect.

Fixes: 4f40afc6c764 ("Bluetooth: Handle BR/EDR devices during suspend")
Signed-off-by: Sonny Sasaka <sonnysasaka@chromium.org>

---
 net/bluetooth/hci_event.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 33d8458fdd4a..6b83da1790ee 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2566,7 +2566,6 @@ static void hci_inquiry_result_evt(struct hci_dev *hdev, struct sk_buff *skb)
 static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_conn_complete *ev = (void *) skb->data;
-	struct inquiry_entry *ie;
 	struct hci_conn *conn;
 
 	BT_DBG("%s", hdev->name);
@@ -2575,13 +2574,19 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 	conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
 	if (!conn) {
-		/* Connection may not exist if auto-connected. Check the inquiry
-		 * cache to see if we've already discovered this bdaddr before.
-		 * If found and link is an ACL type, create a connection class
+		/* Connection may not exist if auto-connected. Check the bredr
+		 * allowlist to see if this device is allowed to auto connect.
+		 * If link is an ACL type, create a connection class
 		 * automatically.
+		 *
+		 * Auto-connect will only occur if the event filter is
+		 * programmed with a given address. Right now, event filter is
+		 * only used during suspend.
 		 */
-		ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
-		if (ie && ev->link_type == ACL_LINK) {
+		if (ev->link_type == ACL_LINK &&
+		    hci_bdaddr_list_lookup_with_flags(&hdev->whitelist,
+						      &ev->bdaddr,
+						      BDADDR_BREDR)) {
 			conn = hci_conn_add(hdev, ev->link_type, &ev->bdaddr,
 					    HCI_ROLE_SLAVE);
 			if (!conn) {
-- 
2.26.2