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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C050C433EF for ; Wed, 6 Oct 2021 23:31:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F54961077 for ; Wed, 6 Oct 2021 23:31:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237338AbhJFXdV (ORCPT ); Wed, 6 Oct 2021 19:33:21 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:53306 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231361AbhJFXdS (ORCPT ); Wed, 6 Oct 2021 19:33:18 -0400 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 702139DC; Thu, 7 Oct 2021 01:31:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1633563083; bh=HUFmwxiZ46w1+hW64n0QX0dQp8cWb6tqfnPkGfaXtdQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QE98plgCTTwn6JjHVrOJXMzk1y0YlcggNinsisbb/AEGnDvWntCR2sp/VN3lVJJJ2 sZhvivoeagZusw16RwlTru8hnuITFi+TcyXOVrTcB6VYrAkBdcdqD0FjSACFIFe0te +m9jZW7Gg4lzbtkLMZutQpq/nM5K+q7tNThzT86U= Date: Thu, 7 Oct 2021 02:31:14 +0300 From: Laurent Pinchart To: Pratyush Yadav Cc: Mauro Carvalho Chehab , Nikhil Devshatwar , Tomi Valkeinen , Vignesh Raghavendra , Benoit Parrot , Maxime Ripard , Rob Herring , Sakari Ailus , Niklas =?utf-8?Q?S=C3=B6derlund?= , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH v4 01/11] media: cadence: csi2rx: Unregister v4l2 async notifier Message-ID: References: <20210915120240.21572-1-p.yadav@ti.com> <20210915120240.21572-2-p.yadav@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210915120240.21572-2-p.yadav@ti.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pratyush, Thank you for the patch. On Wed, Sep 15, 2021 at 05:32:30PM +0530, Pratyush Yadav wrote: > The notifier is added to the global notifier list when registered. When > the module is removed, the struct csi2rx_priv in which the notifier is > embedded, is destroyed. As a result the notifier list has a reference to > a notifier that no longer exists. This causes invalid memory accesses > when the list is iterated over. Similar for when the probe fails. > > Unregister and clean up the notifier to avoid this. > > Fixes: 1fc3b37f34f6 ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver") > Signed-off-by: Pratyush Yadav Reviewed-by: Laurent Pinchart Note that there are other issues in the driver in cleanup paths, in particular a missing v4l2_async_notifier_cleanup() call in csi2rx_parse_dt() when v4l2_async_notifier_add_fwnode_remote_subdev() fails (moving the one from the other error path to an err label would be best), and missing media_entity_cleanup() calls in both the probe error path and the remove handler. Would you like to submit fixes for those ? > --- > > (no changes since v3) > > Changes in v3: > - New in v3. > > drivers/media/platform/cadence/cdns-csi2rx.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c > index 7b44ab2b8c9a..d60975f905d6 100644 > --- a/drivers/media/platform/cadence/cdns-csi2rx.c > +++ b/drivers/media/platform/cadence/cdns-csi2rx.c > @@ -469,6 +469,7 @@ static int csi2rx_probe(struct platform_device *pdev) > return 0; > > err_cleanup: > + v4l2_async_nf_unregister(&csi2rx->notifier); > v4l2_async_nf_cleanup(&csi2rx->notifier); > err_free_priv: > kfree(csi2rx); > @@ -479,6 +480,8 @@ static int csi2rx_remove(struct platform_device *pdev) > { > struct csi2rx_priv *csi2rx = platform_get_drvdata(pdev); > > + v4l2_async_nf_unregister(&csi2rx->notifier); > + v4l2_async_nf_cleanup(&csi2rx->notifier); > v4l2_async_unregister_subdev(&csi2rx->subdev); > kfree(csi2rx); > -- Regards, Laurent Pinchart