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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F45FC6FA82 for ; Wed, 7 Sep 2022 12:46:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229838AbiIGMqe (ORCPT ); Wed, 7 Sep 2022 08:46:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbiIGMqb (ORCPT ); Wed, 7 Sep 2022 08:46:31 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE152B99DF; Wed, 7 Sep 2022 05:46:30 -0700 (PDT) Received: from [192.168.1.111] (91-158-154-79.elisa-laajakaista.fi [91.158.154.79]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id D7E246DD; Wed, 7 Sep 2022 14:46:28 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1662554789; bh=eVJHmAx1xqqZnUZxB7fFigoK7ybBTgGYCFbWTRpq9x4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=f7cYNfp6DK8sWV/fU5SshfhcQLf8ecnZtjtd+lEi4xUELxO9E6tnP6fj6d1C/VNOA xIxxyoy4DPKsFtJyi63cot52dgnOWOyU1e6FSXLElwjqzZ1CrZt4W1eKDG7tCz7r8h GuLyTxXEBiUIuL2ziRWxgOmB+2lV4cKMvaGHA7o0= Message-ID: Date: Wed, 7 Sep 2022 15:46:26 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH] media: staging/intel-ipu3: Finalize subdev initialization to allcoate active state Content-Language: en-US To: Maximilian Luz , Sakari Ailus Cc: Bingbu Cao , Tianshu Qiu , Mauro Carvalho Chehab , Greg Kroah-Hartman , Laurent Pinchart , Jacopo Mondi , Hans Verkuil , linux-media@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org References: <20220907123359.1275322-1-luzmaximilian@gmail.com> From: Tomi Valkeinen In-Reply-To: <20220907123359.1275322-1-luzmaximilian@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Maximilian, On 07/09/2022 15:33, Maximilian Luz wrote: > Commit f69952a4dc1e ("media: subdev: add active state to struct > v4l2_subdev") introduced the active_state member to struct v4l2_subdev. > This state needs to be allocated via v4l2_subdev_init_finalize(). The > intel-ipu3 driver unfortunately does not do that, due to which, That is fine, a driver only needs to allocate the active state if it uses the active state. > active_state is NULL and we run into an oops (NULL pointer dereference) > when that state is accessed. > > In particular, this happens subdev in IOCTLs as commit 3cc7a4bbc381 > ("media: subdev: pass also the active state to subdevs from ioctls") > passes that state on to the subdev IOCTLs. An example scenario where > this happens is running libcamera's qcam or cam on a device with IPU3, > for example the Microsoft Surface Book 2. In this case, the oops is > reproducibly in v4l2_subdev_get_try_crop(), called via > imgu_subdev_set_selection(). > > To fix this, allocate the active_state member via > v4l2_subdev_init_finalize(). This is not a correct fix. Sakari has sent (and maybe pushed?) this: https://lore.kernel.org/all/20220825190351.3241444-1-sakari.ailus@linux.intel.com/ Tomi > Link: https://github.com/linux-surface/linux-surface/issues/907 > Fixes: 3cc7a4bbc381 ("media: subdev: pass also the active state to subdevs from ioctls") > Signed-off-by: Maximilian Luz > --- > drivers/staging/media/ipu3/ipu3-v4l2.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/media/ipu3/ipu3-v4l2.c b/drivers/staging/media/ipu3/ipu3-v4l2.c > index d1c539cefba8..84ab98ba9a2e 100644 > --- a/drivers/staging/media/ipu3/ipu3-v4l2.c > +++ b/drivers/staging/media/ipu3/ipu3-v4l2.c > @@ -1093,10 +1093,18 @@ static int imgu_v4l2_subdev_register(struct imgu_device *imgu, > "failed to create subdev v4l2 ctrl with err %d", r); > goto fail_subdev; > } > + > + r = v4l2_subdev_init_finalize(&imgu_sd->subdev); > + if (r) { > + dev_err(&imgu->pci_dev->dev, > + "failed to initialize subdev (%d)\n", r); > + goto fail_subdev; > + } > + > r = v4l2_device_register_subdev(&imgu->v4l2_dev, &imgu_sd->subdev); > if (r) { > dev_err(&imgu->pci_dev->dev, > - "failed initialize subdev (%d)\n", r); > + "failed to register subdev (%d)\n", r); > goto fail_subdev; > } > > @@ -1104,6 +1112,7 @@ static int imgu_v4l2_subdev_register(struct imgu_device *imgu, > return 0; > > fail_subdev: > + v4l2_subdev_cleanup(&imgu_sd->subdev); > v4l2_ctrl_handler_free(imgu_sd->subdev.ctrl_handler); > media_entity_cleanup(&imgu_sd->subdev.entity); > > @@ -1275,6 +1284,7 @@ static void imgu_v4l2_subdev_cleanup(struct imgu_device *imgu, unsigned int i) > struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[i]; > > v4l2_device_unregister_subdev(&imgu_pipe->imgu_sd.subdev); > + v4l2_subdev_cleanup(&imgu_pipe->imgu_sd.subdev); > v4l2_ctrl_handler_free(imgu_pipe->imgu_sd.subdev.ctrl_handler); > media_entity_cleanup(&imgu_pipe->imgu_sd.subdev.entity); > }