From: Avichal Rakesh Date: Thu, 4 Jan 2024 21:50:09 +0000 (-0800) Subject: usb: gadget: uvc: Remove nested locking X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9866dc4314c6c858e451933f965d64532aec00a9;p=linux.git usb: gadget: uvc: Remove nested locking 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. Fixes: 6acba0345b68 ("usb:gadget:uvc Do not use worker thread to pump isoc usb requests") Signed-off-by: Avichal Rakesh Link: https://lore.kernel.org/r/20240104215009.2252452-2-arakesh@google.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 7f18dc471be38..dd3241fc6939d 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