From db317a37229b2dd338c4b9348310ca47e462ca67 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 14 Jun 2021 12:34:09 +0200 Subject: [PATCH] media: subdev: disallow ioctl for saa6588/davinci commit 0a7790be182d32b9b332a37cb4206e24fe94b728 upstream. 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 Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- 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 8824dd0fb331..35a51e9b539d 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -3187,7 +3187,7 @@ 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; @@ -3268,7 +3268,7 @@ 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; } @@ -3289,7 +3289,7 @@ 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 9a6a6b68f8e3..85d082baaadc 100644 --- a/drivers/media/pci/saa7134/saa7134-video.c +++ b/drivers/media/pci/saa7134/saa7134-video.c @@ -1178,7 +1178,7 @@ 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; @@ -1197,7 +1197,7 @@ 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; @@ -1213,7 +1213,7 @@ 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 1de960bfcab9..73150520c02d 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,