From patchwork Mon Jan 4 20:34:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ezequiel Garcia X-Patchwork-Id: 356544 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68A5EC433DB for ; Mon, 4 Jan 2021 20:35:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28E6C2225E for ; Mon, 4 Jan 2021 20:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727764AbhADUfe (ORCPT ); Mon, 4 Jan 2021 15:35:34 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:35478 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727403AbhADUfe (ORCPT ); Mon, 4 Jan 2021 15:35:34 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id C55061F44F08 From: Ezequiel Garcia To: linux-media@vger.kernel.org, Hans Verkuil Cc: kernel@collabora.com, Laurent Pinchart , Steve Longerbeam , Philipp Zabel , NXP Linux Team , Ezequiel Garcia Subject: [PATCH v2 2/3] media: imx: Fix csc/scaler unregister Date: Mon, 4 Jan 2021 17:34:40 -0300 Message-Id: <20210104203441.168778-2-ezequiel@collabora.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210104203441.168778-1-ezequiel@collabora.com> References: <20210104203441.168778-1-ezequiel@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The csc/scaler device private struct is released by ipu_csc_scaler_video_device_release(), which can be called by video_unregister_device() if there are no users of the underlying struct video device. Therefore, the mutex can't be held when calling video_unregister_device() as its memory may be freed by it, leading to a kernel oops. Fortunately, the fix is quite simple as no locking is needed when calling video_unregister_device(): v4l2-core already has its own internal locking, and the structures are also properly refcounted. Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device") Signed-off-by: Ezequiel Garcia Reviewed-by: Philipp Zabel --- drivers/staging/media/imx/imx-media-csc-scaler.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/staging/media/imx/imx-media-csc-scaler.c b/drivers/staging/media/imx/imx-media-csc-scaler.c index fab1155a5958..63a0204502a8 100644 --- a/drivers/staging/media/imx/imx-media-csc-scaler.c +++ b/drivers/staging/media/imx/imx-media-csc-scaler.c @@ -869,11 +869,7 @@ void imx_media_csc_scaler_device_unregister(struct imx_media_video_dev *vdev) struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev); struct video_device *vfd = priv->vdev.vfd; - mutex_lock(&priv->mutex); - video_unregister_device(vfd); - - mutex_unlock(&priv->mutex); } struct imx_media_video_dev *