usb: Fix possible SET ADDRESS data corruption

The address from the packet needs to be saved before sending
the response -- after the response the request being pointed
to could get overwritten. This used to be done correctly but
I unintentionally broke it when updating the handler to the
new control request API.

Change-Id: I9b11548baf20dce44a82301731405dc8e8f1cef3

1 files changed, 5 insertions, 2 deletions

diff --git a/firmware/usbstack/usb_core.c b/firmware/usbstack/usb_core.c
index 5de892196d..738b92ed4d 100644
--- a/firmware/usbstack/usb_core.c
+++ b/firmware/usbstack/usb_core.c
@@ -729,6 +729,8 @@ static void usb_core_do_clear_feature(int recip, int recip_nr, int feature)
 
 static void request_handler_device(struct usb_ctrlrequest* req, void* reqdata)
 {
+    unsigned address;
+
     switch(req->bRequest) {
         case USB_REQ_GET_CONFIGURATION:
             logf("usb_core: GET_CONFIG");
@@ -744,10 +746,11 @@ static void request_handler_device(struct usb_ctrlrequest* req, void* reqdata)
             /* NOTE: We really have no business handling this and drivers
              * should just handle it themselves. We don't care beyond
              * knowing if we've been assigned an address yet, or not. */
+            address = req->wValue;
             usb_drv_control_response(USB_CONTROL_ACK, NULL, 0);
             usb_drv_cancel_all_transfers();
-            usb_drv_set_address(req->wValue);
-            usb_core_do_set_addr(req->wValue);
+            usb_drv_set_address(address);
+            usb_core_do_set_addr(address);
             break;
         case USB_REQ_GET_DESCRIPTOR:
             logf("usb_core: GET_DESC %d", req->wValue >> 8);