From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B618872 for ; Mon, 14 Jun 2021 17:21:26 +0000 (UTC) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id D1DC4436; Mon, 14 Jun 2021 19:21:24 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1623691285; bh=aKY7UtieT5exgbf/JPK7G/X0gPU3KnH1SU01c4l8VCk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Vdwc4+tSLnL557QeggHLPZ1vC/x5dMSJIfcrM8CG6W+DZWbkHs7lbNa9PZPGnNmeZ /o2+qHpqr9/F9PqSGjyHDwu06s5qcMOK09yWZdF1Or7BeSS0QTavkh21+uuaSTfNY4 UxpBmmLHQezCQUHeGQHeQwCCMbLAbhnhnE3ewT7s= Date: Mon, 14 Jun 2021 20:21:05 +0300 From: Laurent Pinchart To: Arnd Bergmann Cc: Hans Verkuil , Mauro Carvalho Chehab , Arnd Bergmann , "Lad, Prabhakar" , Eduardo Valentin , Sakari Ailus , Greg Kroah-Hartman , Vaibhav Gupta , Liu Shixin , Jacopo Mondi , Andy Shevchenko , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-staging@lists.linux.dev, stable@vger.kernel.org Subject: Re: [PATCH v3 8/8] media: subdev: disallow ioctl for saa6588/davinci Message-ID: References: <20210614103409.3154127-1-arnd@kernel.org> <20210614103409.3154127-9-arnd@kernel.org> X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210614103409.3154127-9-arnd@kernel.org> Hi Arnd, Thank you for the patch. On Mon, Jun 14, 2021 at 12:34:09PM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann > > The saa6588_ioctl() function expects to get called from other kernel > functions with a 'saa6588_command' pointer, but I found nothing stops it > from getting called from user space instead, which seems rather dangerous. > > The same thing happens in the davinci vpbe driver with its VENC_GET_FLD > command. > > As a quick fix, add a separate .command() callback pointer for this > driver and change the two callers over to that. This change can easily > get backported to stable kernels if necessary, but since there are only > two drivers, we may want to eventually replace this with a set of more > specialized callbacks in the long run. > > Fixes: c3fda7f835b0 ("V4L/DVB (10537): saa6588: convert to v4l2_subdev.") > Cc: stable@vger.kernel.org > Signed-off-by: Arnd Bergmann Reviewed-by: Laurent Pinchart > --- > drivers/media/i2c/saa6588.c | 4 ++-- > drivers/media/pci/bt8xx/bttv-driver.c | 6 +++--- > drivers/media/pci/saa7134/saa7134-video.c | 6 +++--- > drivers/media/platform/davinci/vpbe_display.c | 2 +- > drivers/media/platform/davinci/vpbe_venc.c | 6 ++---- > include/media/v4l2-subdev.h | 4 ++++ > 6 files changed, 15 insertions(+), 13 deletions(-) > > diff --git a/drivers/media/i2c/saa6588.c b/drivers/media/i2c/saa6588.c > index ecb491d5f2ab..d1e0716bdfff 100644 > --- a/drivers/media/i2c/saa6588.c > +++ b/drivers/media/i2c/saa6588.c > @@ -380,7 +380,7 @@ static void saa6588_configure(struct saa6588 *s) > > /* ---------------------------------------------------------------------- */ > > -static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg) > +static long saa6588_command(struct v4l2_subdev *sd, unsigned int cmd, void *arg) > { > struct saa6588 *s = to_saa6588(sd); > struct saa6588_command *a = arg; > @@ -433,7 +433,7 @@ static int saa6588_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *vt) > /* ----------------------------------------------------------------------- */ > > static const struct v4l2_subdev_core_ops saa6588_core_ops = { > - .ioctl = saa6588_ioctl, > + .command = saa6588_command, > }; > > static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = { > diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c > index 1f62a9d8ea1d..0e9df8b35ac6 100644 > --- a/drivers/media/pci/bt8xx/bttv-driver.c > +++ b/drivers/media/pci/bt8xx/bttv-driver.c > @@ -3179,7 +3179,7 @@ static int radio_release(struct file *file) > > btv->radio_user--; > > - bttv_call_all(btv, core, ioctl, SAA6588_CMD_CLOSE, &cmd); > + bttv_call_all(btv, core, command, SAA6588_CMD_CLOSE, &cmd); > > if (btv->radio_user == 0) > btv->has_radio_tuner = 0; > @@ -3260,7 +3260,7 @@ static ssize_t radio_read(struct file *file, char __user *data, > cmd.result = -ENODEV; > radio_enable(btv); > > - bttv_call_all(btv, core, ioctl, SAA6588_CMD_READ, &cmd); > + bttv_call_all(btv, core, command, SAA6588_CMD_READ, &cmd); > > return cmd.result; > } > @@ -3281,7 +3281,7 @@ static __poll_t radio_poll(struct file *file, poll_table *wait) > cmd.instance = file; > cmd.event_list = wait; > cmd.poll_mask = res; > - bttv_call_all(btv, core, ioctl, SAA6588_CMD_POLL, &cmd); > + bttv_call_all(btv, core, command, SAA6588_CMD_POLL, &cmd); > > return cmd.poll_mask; > } > diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c > index 0f9d6b9edb90..374c8e1087de 100644 > --- a/drivers/media/pci/saa7134/saa7134-video.c > +++ b/drivers/media/pci/saa7134/saa7134-video.c > @@ -1181,7 +1181,7 @@ static int video_release(struct file *file) > > saa_call_all(dev, tuner, standby); > if (vdev->vfl_type == VFL_TYPE_RADIO) > - saa_call_all(dev, core, ioctl, SAA6588_CMD_CLOSE, &cmd); > + saa_call_all(dev, core, command, SAA6588_CMD_CLOSE, &cmd); > mutex_unlock(&dev->lock); > > return 0; > @@ -1200,7 +1200,7 @@ static ssize_t radio_read(struct file *file, char __user *data, > cmd.result = -ENODEV; > > mutex_lock(&dev->lock); > - saa_call_all(dev, core, ioctl, SAA6588_CMD_READ, &cmd); > + saa_call_all(dev, core, command, SAA6588_CMD_READ, &cmd); > mutex_unlock(&dev->lock); > > return cmd.result; > @@ -1216,7 +1216,7 @@ static __poll_t radio_poll(struct file *file, poll_table *wait) > cmd.event_list = wait; > cmd.poll_mask = 0; > mutex_lock(&dev->lock); > - saa_call_all(dev, core, ioctl, SAA6588_CMD_POLL, &cmd); > + saa_call_all(dev, core, command, SAA6588_CMD_POLL, &cmd); > mutex_unlock(&dev->lock); > > return rc | cmd.poll_mask; > diff --git a/drivers/media/platform/davinci/vpbe_display.c b/drivers/media/platform/davinci/vpbe_display.c > index d19bad997f30..bf3c3e76b921 100644 > --- a/drivers/media/platform/davinci/vpbe_display.c > +++ b/drivers/media/platform/davinci/vpbe_display.c > @@ -47,7 +47,7 @@ static int venc_is_second_field(struct vpbe_display *disp_dev) > > ret = v4l2_subdev_call(vpbe_dev->venc, > core, > - ioctl, > + command, > VENC_GET_FLD, > &val); > if (ret < 0) { > diff --git a/drivers/media/platform/davinci/vpbe_venc.c b/drivers/media/platform/davinci/vpbe_venc.c > index 8caa084e5704..bde241c26d79 100644 > --- a/drivers/media/platform/davinci/vpbe_venc.c > +++ b/drivers/media/platform/davinci/vpbe_venc.c > @@ -521,9 +521,7 @@ static int venc_s_routing(struct v4l2_subdev *sd, u32 input, u32 output, > return ret; > } > > -static long venc_ioctl(struct v4l2_subdev *sd, > - unsigned int cmd, > - void *arg) > +static long venc_command(struct v4l2_subdev *sd, unsigned int cmd, void *arg) > { > u32 val; > > @@ -542,7 +540,7 @@ static long venc_ioctl(struct v4l2_subdev *sd, > } > > static const struct v4l2_subdev_core_ops venc_core_ops = { > - .ioctl = venc_ioctl, > + .command = venc_command, > }; > > static const struct v4l2_subdev_video_ops venc_video_ops = { > diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h > index 42aa1f6c7c3f..115b1e41e933 100644 > --- a/include/media/v4l2-subdev.h > +++ b/include/media/v4l2-subdev.h > @@ -162,6 +162,9 @@ struct v4l2_subdev_io_pin_config { > * @s_gpio: set GPIO pins. Very simple right now, might need to be extended with > * a direction argument if needed. > * > + * @command: called by in-kernel drivers in order to call functions internal > + * to subdev drivers driver that have a separate callback. > + * > * @ioctl: called at the end of ioctl() syscall handler at the V4L2 core. > * used to provide support for private ioctls used on the driver. > * > @@ -193,6 +196,7 @@ struct v4l2_subdev_core_ops { > int (*load_fw)(struct v4l2_subdev *sd); > int (*reset)(struct v4l2_subdev *sd, u32 val); > int (*s_gpio)(struct v4l2_subdev *sd, u32 val); > + long (*command)(struct v4l2_subdev *sd, unsigned int cmd, void *arg); > long (*ioctl)(struct v4l2_subdev *sd, unsigned int cmd, void *arg); > #ifdef CONFIG_COMPAT > long (*compat_ioctl32)(struct v4l2_subdev *sd, unsigned int cmd, void *arg); -- Regards, Laurent Pinchart