From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6DE90225AF; Thu, 4 Jan 2024 14:19:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="y+wgYxLh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 947D2C433C7; Thu, 4 Jan 2024 14:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1704377968; bh=jfnWO+JhZ4QPmax+cqjet6QLqg4coqHv8g8OKRTw41c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=y+wgYxLhjaiAbtjS6xuSM71IeKT3NCQicLyvnoOM+xrlFNibRaqT7s4YbegOyW2Ej FKTLxvCvlBnvwpmPz3JZmU6/iTV5OdlYnfpSdXlotw64cCws0Uq58Celyr+q06UjYM ldx7wgtn9/lQR/VHRmpt05aLJ2rHfau2rMCAi/s0= Date: Thu, 4 Jan 2024 15:19:26 +0100 From: Greg KH To: Avichal Rakesh Cc: dan.scally@ideasonboard.com, laurent.pinchart@ideasonboard.com, etalvala@google.com, jchowdhary@google.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH 2/2] usb: gadget: uvc: Remove nested locking Message-ID: <2024010416-stilt-magical-d711@gregkh> References: <20231215210746.821494-1-arakesh@google.com> <20231215210746.821494-2-arakesh@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231215210746.821494-2-arakesh@google.com> 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 > --- > 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