This is a note to let you know that I've just added the patch titled
Bluetooth: vhci: Fix race when opening vhci device
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bluetooth-vhci-fix-race-when-opening-vhci-device.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 92d4abd66f7080075793970fc8f241239e58a9e7 Mon Sep 17 00:00:00 2001
From: Arkadiusz Bokowy <arkadiusz.bokowy@xxxxxxxxx>
Date: Wed, 20 Sep 2023 17:30:07 +0200
Subject: Bluetooth: vhci: Fix race when opening vhci device
From: Arkadiusz Bokowy <arkadiusz.bokowy@xxxxxxxxx>
commit 92d4abd66f7080075793970fc8f241239e58a9e7 upstream.
When the vhci device is opened in the two-step way, i.e.: open device
then write a vendor packet with requested controller type, the device
shall respond with a vendor packet which includes HCI index of created
interface.
When the virtual HCI is created, the host sends a reset request to the
controller. This request is processed by the vhci_send_frame() function.
However, this request is send by a different thread, so it might happen
that this HCI request will be received before the vendor response is
queued in the read queue. This results in the HCI vendor response and
HCI reset request inversion in the read queue which leads to improper
behavior of btvirt:
> dmesg
[1754256.640122] Bluetooth: MGMT ver 1.22
[1754263.023806] Bluetooth: MGMT ver 1.22
[1754265.043775] Bluetooth: hci1: Opcode 0x c03 failed: -110
In order to synchronize vhci two-step open/setup process with virtual
HCI initialization, this patch adds internal lock when queuing data in
the vhci_send_frame() function.
Signed-off-by: Arkadiusz Bokowy <arkadiusz.bokowy@xxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/bluetooth/hci_vhci.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -67,7 +67,10 @@ static int vhci_send_frame(struct hci_de
struct vhci_data *data = hci_get_drvdata(hdev);
memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
+
+ mutex_lock(&data->open_mutex);
skb_queue_tail(&data->readq, skb);
+ mutex_unlock(&data->open_mutex);
wake_up_interruptible(&data->read_wait);
return 0;
Patches currently in stable-queue which might be from arkadiusz.bokowy@xxxxxxxxx are
queue-5.15/bluetooth-vhci-fix-race-when-opening-vhci-device.patch
