4 files changed, 56 insertions, 6 deletions

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 135dfac..3a3f7b4 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -515,8 +515,8 @@ int hci_uuids_clear(struct hci_dev *hdev);
 
 int hci_link_keys_clear(struct hci_dev *hdev);
 struct link_key *hci_find_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);
-int hci_add_link_key(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
-						u8 *key, u8 type, u8 pin_len);
+int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
+			bdaddr_t *bdaddr, u8 *val, u8 type, u8 pin_len);
 int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);
 
 int hci_remote_oob_data_clear(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 07d0ba3..5f55aef 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1022,8 +1022,44 @@ struct link_key *hci_find_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr)
 	return NULL;
 }
 
-int hci_add_link_key(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
-						u8 *val, u8 type, u8 pin_len)
+static int hci_persistent_key(struct hci_dev *hdev, struct hci_conn *conn,
+						u8 key_type, u8 old_key_type)
+{
+	/* Legacy key */
+	if (key_type < 0x03)
+		return 1;
+
+	/* Debug keys are insecure so don't store them persistently */
+	if (key_type == HCI_LK_DEBUG_COMBINATION)
+		return 0;
+
+	/* Changed combination key and there's no previous one */
+	if (key_type == HCI_LK_CHANGED_COMBINATION && old_key_type == 0xff)
+		return 0;
+
+	/* Security mode 3 case */
+	if (!conn)
+		return 1;
+
+	/* Neither local nor remote side had no-bonding as requirement */
+	if (conn->auth_type > 0x01 && conn->remote_auth > 0x01)
+		return 1;
+
+	/* Local side had dedicated bonding as requirement */
+	if (conn->auth_type == 0x02 || conn->auth_type == 0x03)
+		return 1;
+
+	/* Remote side had dedicated bonding as requirement */
+	if (conn->remote_auth == 0x02 || conn->remote_auth == 0x03)
+		return 1;
+
+	/* If none of the above criteria match, then don't store the key
+	 * persistently */
+	return 0;
+}
+
+int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
+				bdaddr_t *bdaddr, u8 *val, u8 type, u8 pin_len)
 {
 	struct link_key *key, *old_key;
 	u8 old_key_type;
@@ -1042,6 +1078,20 @@ int hci_add_link_key(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
 
 	BT_DBG("%s key for %s type %u", hdev->name, batostr(bdaddr), type);
 
+	/* Some buggy controller combinations generate a changed
+	 * combination key for legacy pairing even when there's no
+	 * previous key */
+	if (type == HCI_LK_CHANGED_COMBINATION &&
+					(!conn || conn->remote_auth == 0xff) &&
+					old_key_type == 0xff)
+		type = HCI_LK_COMBINATION;
+
+	if (new_key && !hci_persistent_key(hdev, conn, type, old_key_type)) {
+		list_del(&key->list);
+		kfree(key);
+		return 0;
+	}
+
 	bacpy(&key->bdaddr, bdaddr);
 	memcpy(key->val, val, 16);
 	key->type = type;
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index ebbaa6c..8a63d3a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2136,7 +2136,7 @@ static inline void hci_link_key_notify_evt(struct hci_dev *hdev, struct sk_buff
 	}
 
 	if (test_bit(HCI_LINK_KEYS, &hdev->flags))
-		hci_add_link_key(hdev, 1, &ev->bdaddr, ev->link_key,
+		hci_add_link_key(hdev, conn, 1, &ev->bdaddr, ev->link_key,
 							ev->key_type, pin_len);
 
 	hci_dev_unlock(hdev);
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index a1b0ec4..e1384fc 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -945,7 +945,7 @@ static int load_keys(struct sock *sk, u16 index, unsigned char *data, u16 len)
 	for (i = 0; i < key_count; i++) {
 		struct mgmt_key_info *key = &cp->keys[i];
 
-		hci_add_link_key(hdev, 0, &key->bdaddr, key->val, key->type,
+		hci_add_link_key(hdev, NULL, 0, &key->bdaddr, key->val, key->type,
 								key->pin_len);
 	}