Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Piyush Mehta <piyush.mehta@amd.com>
To:     <laurent.pinchart@ideasonboard.com>, <dan.scally@ideasonboard.com>,
        <michal.simek@amd.com>, <gregkh@linuxfoundation.org>
CC:     <siva.durga.prasad.paladugu@amd.com>,
        <radhey.shyam.pandey@amd.com>, <linux-usb@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, Piyush Mehta <piyush.mehta@amd.com>
Subject: [PATCH] usb: gadget: uvc_video: unlock before submitting a request to ep
Date:   Thu, 2 Nov 2023 12:41:38 +0530
Message-ID: <20231102071138.828126-1-piyush.mehta@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Nov 2023 07:11:57.2731
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: f2293b27-2c0a-4335-7b04-08dbdb73002e
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000EDD2.namprd03.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5122
X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=no autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (snail.vger.email [0.0.0.0]); Thu, 02 Nov 2023 00:12:35 -0700 (PDT)

There could be chances where the usb_ep_queue() could fail and trigger
complete() handler with error status. In this case, if usb_ep_queue()
is called with lock held and the triggered complete() handler is waiting
for the same lock to be cleared could result in a deadlock situation and
could result in system hang. To aviod this scenerio, call usb_ep_queue()
with lock removed. This patch does the same.

Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
---
 drivers/usb/gadget/function/uvc_video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 91af3b1ef0d4..0a5d9ac145e7 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -460,11 +460,12 @@ static void uvcg_video_pump(struct work_struct *work)
 			req->no_interrupt = 1;
 		}
 
-		/* Queue the USB request */
-		ret = uvcg_video_ep_queue(video, req);
 		spin_unlock_irqrestore(&queue->irqlock, flags);
 
+		/* Queue the USB request */
+		ret = uvcg_video_ep_queue(video, req);
 		if (ret < 0) {
+			usb_ep_set_halt(video->ep);
 			uvcg_queue_cancel(queue, 0);
 			break;
 		}
-- 
2.25.1