diff options
| author | Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> | 2021-07-28 15:51:04 +0800 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2021-07-29 13:37:29 +0200 |
| commit | 92fe24a7db751b80925214ede43f8d2be792ea7b (patch) | |
| tree | 6fe57117afa4272754715d04a63baf56a06f2202 /net/bluetooth | |
| parent | a25fca4d3c18766b6f7a3c95fa8faec23ef464c5 (diff) | |
Bluetooth: skip invalid hci_sync_conn_complete_evt
Syzbot reported a corrupted list in kobject_add_internal [1]. This
happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with
status 0 are sent for the same HCI connection. This causes us to
register the device more than once which corrupts the kset list.
As this is forbidden behavior, we add a check for whether we're
trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple
times for one connection. If that's the case, the event is invalid, so
we report an error that the device is misbehaving, and ignore the
packet.
Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1]
Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/hci_event.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 1c3018202564..ea7fc09478be 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4382,6 +4382,21 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev, switch (ev->status) { case 0x00: + /* The synchronous connection complete event should only be + * sent once per new connection. Receiving a successful + * complete event when the connection status is already + * BT_CONNECTED means that the device is misbehaving and sent + * multiple complete event packets for the same new connection. + * + * Registering the device more than once can corrupt kernel + * memory, hence upon detecting this invalid event, we report + * an error and ignore the packet. + */ + if (conn->state == BT_CONNECTED) { + bt_dev_err(hdev, "Ignoring connect complete event for existing connection"); + goto unlock; + } + conn->handle = __le16_to_cpu(ev->handle); conn->state = BT_CONNECTED; conn->type = ev->link_type; |