| Message ID | 20231215210746.821494-2-arakesh@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] usb: gadget: uvc: Fix use are free during STREAMOFF | expand |
On Fri, Dec 15, 2023 at 01:07:45PM -0800, Avichal Rakesh wrote: > When handling error status from uvcg_video_usb_req_queue, > uvc_video_complete currently calls uvcg_queue_cancel with > video->req_lock held. uvcg_queue_cancel internally locks > queue->irqlock, which nests queue->irqlock inside > video->req_lock. This isn't a functional bug at the > moment, but does open up possibilities for ABBA > deadlocks in the future. > > This patch fixes the accidental nesting by dropping > video->req_lock before calling uvcg_queue_cancel. > > Signed-off-by: Avichal Rakesh <arakesh@google.com> > --- > drivers/usb/gadget/function/uvc_video.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) Again, what commit does this fix? thanks, greg k-h
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index e5db1be14ca3..d15b9b4c4fcc 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -469,13 +469,15 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) * Put request back in req_free for it to be cleaned * up later. */ - uvcg_queue_cancel(queue, 0); list_add_tail(&to_queue->list, &video->req_free); } } else { uvc_video_free_request(ureq, ep); + ret = 0; } spin_unlock_irqrestore(&video->req_lock, flags); + if (ret < 0) + uvcg_queue_cancel(queue, 0); } static int
When handling error status from uvcg_video_usb_req_queue, uvc_video_complete currently calls uvcg_queue_cancel with video->req_lock held. uvcg_queue_cancel internally locks queue->irqlock, which nests queue->irqlock inside video->req_lock. This isn't a functional bug at the moment, but does open up possibilities for ABBA deadlocks in the future. This patch fixes the accidental nesting by dropping video->req_lock before calling uvcg_queue_cancel. Signed-off-by: Avichal Rakesh <arakesh@google.com> --- drivers/usb/gadget/function/uvc_video.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)