[PATCH v3] bluetooth: guard against controllers sending zero'd events

[PATCH v3] bluetooth: guard against controllers sending zero'd events

[Alain Michaud]

Some controllers have been observed to send zero'd events under some
conditions.  This change guards against this condition as well as adding
a trace to facilitate diagnosability of this condition.

Signed-off-by: Alain Michaud <alainm@chromium.org>
---

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

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 591e7477e925..a40ed31f6eb8 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5868,6 +5868,11 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 	u8 status = 0, event = hdr->evt, req_evt = 0;
 	u16 opcode = HCI_OP_NOP;
 
+	if (!event) {
+		bt_dev_warn(hdev, "Received unexpected HCI Event 00000000");
+		goto done;
+	}
+
 	if (hdev->sent_cmd && bt_cb(hdev->sent_cmd)->hci.req_event == event) {
 		struct hci_command_hdr *cmd_hdr = (void *) hdev->sent_cmd->data;
 		opcode = __le16_to_cpu(cmd_hdr->opcode);
@@ -6079,6 +6084,7 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 		req_complete_skb(hdev, status, opcode, orig_skb);
 	}
 
+done:
 	kfree_skb(orig_skb);
 	kfree_skb(skb);
 	hdev->stat.evt_rx++;
-- 
2.25.1.481.gfbce0eb801-goog

Re: [PATCH v3] bluetooth: guard against controllers sending zero'd events

[Marcel Holtmann]

Hi Alain,

> Some controllers have been observed to send zero'd events under some
> conditions.  This change guards against this condition as well as adding
> a trace to facilitate diagnosability of this condition.
> 
> Signed-off-by: Alain Michaud <alainm@chromium.org>
> ---
> 
> net/bluetooth/hci_event.c | 6 ++++++
> 1 file changed, 6 insertions(+)

patch has been applied to bluetooth-next tree.

Regards

Marcel

Re: [PATCH v3] bluetooth: guard against controllers sending zero'd events

[Alain Michaud]

Thanks Marcel.


On Wed, Mar 4, 2020 at 2:28 AM Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Alain,
>
> > Some controllers have been observed to send zero'd events under some
> > conditions.  This change guards against this condition as well as adding
> > a trace to facilitate diagnosability of this condition.
> >
> > Signed-off-by: Alain Michaud <alainm@chromium.org>
> > ---
> >
> > net/bluetooth/hci_event.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
>
> patch has been applied to bluetooth-next tree.
>
> Regards
>
> Marcel
>