@@ -3887,8 +3887,10 @@ int hci_dev_open_sync(struct hci_dev *hdev)
hci_dev_test_flag(hdev, HCI_VENDOR_DIAG) && hdev->set_diag)
ret = hdev->set_diag(hdev, true);
- msft_do_open(hdev);
- aosp_do_open(hdev);
+ if (!hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) {
+ msft_do_open(hdev);
+ aosp_do_open(hdev);
+ }
clear_bit(HCI_INIT, &hdev->flags);
@@ -4031,8 +4033,10 @@ int hci_dev_close_sync(struct hci_dev *hdev)
hci_sock_dev_event(hdev, HCI_DEV_DOWN);
- aosp_do_close(hdev);
- msft_do_close(hdev);
+ if (!hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) {
+ aosp_do_close(hdev);
+ msft_do_close(hdev);
+ }
if (hdev->flush)
hdev->flush(hdev);
A race condition is triggered when usermode control is given to userspace before the kernel's MSFT query responds, resulting in an unexpected response to userspace's reset command. Issue can be observed in btmon: < HCI Command: Vendor (0x3f|0x001e) plen 2 #3 [hci0] 05 01 .. @ USER Open: bt_stack_manage (privileged) version 2.22 {0x0002} [hci0] < HCI Command: Reset (0x03|0x0003) plen 0 #4 [hci0] > HCI Event: Command Complete (0x0e) plen 5 #5 [hci0] Vendor (0x3f|0x001e) ncmd 1 Status: Command Disallowed (0x0c) 05 . > HCI Event: Command Complete (0x0e) plen 4 #6 [hci0] Reset (0x03|0x0003) ncmd 2 Status: Success (0x00) Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org> Signed-off-by: Jesse Melhuish <melhuishj@chromium.org> --- Changes in v3: - Added guard around *_close calls as well. Changes in v2: - Moved guard to the new home for this code. net/bluetooth/hci_sync.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)