From mboxrd@z Thu Jan 1 00:00:00 1970 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 9AF19C46461 for ; Tue, 2 Mar 2021 01:19:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60E9160C3E for ; Tue, 2 Mar 2021 01:19:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377557AbhCBArr (ORCPT ); Mon, 1 Mar 2021 19:47:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:54534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240255AbhCASpI (ORCPT ); Mon, 1 Mar 2021 13:45:08 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 29DDA6530D; Mon, 1 Mar 2021 17:42:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614620560; bh=dgWkJBRcXmlasYdpr6OICrMX8AOjg3N83L5+6TgI04I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FvHOMZe7SdQ0C4QfhYVWTdfnZKWLPMwgLSh1oZ/UiAt8uX6FcxwiNh/0k8uCAhYa8 hFRlkwcnIukO+A6CizjzzhTgn4g/geC7zxGYTOaRAlqGoOeTG86yofJ5iXPDNDU+Qa tNJI86qBvZpXMhTRICAK6O/NPXovTft8a7xIESEw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ezequiel Garcia , Philipp Zabel , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.11 196/775] media: imx: Fix csc/scaler unregister Date: Mon, 1 Mar 2021 17:06:04 +0100 Message-Id: <20210301161211.329855459@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ezequiel Garcia [ Upstream commit 89b14485caa4b7b2eaf70be0064f0978e68ebeee ] 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 Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- 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 fab1155a5958c..63a0204502a8b 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 * -- 2.27.0