[PATCH v5 01/12] media: uvcvideo: Fix race condition handling events

Ricardo Ribalda
2020-12-21T18:43:32Z

The control and its data needs to be copied to the workqueue at the same
time to avoid half-updates of the events.
This is, events reported to userspace were the control id does not match
its value.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
drivers/media/usb/uvc/uvc_ctrl.c | 2 +-
drivers/media/usb/uvc/uvcvideo.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 011e69427b7c..aa18dcdf8165 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1332,7 +1332,7 @@ bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
return false;
}

- w->data = data;
+ memcpy(w->data, data, ctrl->info.size);
w->urb = urb;
w->chain = chain;
w->ctrl = ctrl;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a3dfacf069c4..0db6c2e0bd98 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -678,7 +678,7 @@ struct uvc_device {
struct urb *urb;
struct uvc_video_chain *chain;
struct uvc_control *ctrl;
- const void *data;
+ u8 data[UVC_MAX_STATUS_SIZE];
} async_ctrl;
};

--
2.29.2.684.gfbc64c5ab5-goog