diff mbox series

[v9,14/22] media: uvcvideo: Check controls flags before accessing them

Message ID 20210326095840.364424-15-ribalda@chromium.org
State Superseded
Headers show
Series uvcvideo: Fix v4l2-compliance errors | expand

Commit Message

Ricardo Ribalda March 26, 2021, 9:58 a.m. UTC
We can figure out if reading/writing a set of controls can fail without
accessing them by checking their flags.

This way we can honor the API closer:

If an error is found when validating the list of controls passed with
VIDIOC_G_EXT_CTRLS, then error_idx shall be set to ctrls->count to
indicate to userspace that no actual hardware was touched.

Fixes v4l2-compliance:
Control ioctls (Input 0):
		warn: v4l2-test-controls.cpp(765): g_ext_ctrls(0) invalid error_idx 0
                fail: v4l2-test-controls.cpp(645): invalid error index write only control
        test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL

Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 22 ++++++++++++++++++
 drivers/media/usb/uvc/uvc_v4l2.c | 39 ++++++++++++++++++++++++++++----
 drivers/media/usb/uvc/uvcvideo.h |  2 ++
 3 files changed, 58 insertions(+), 5 deletions(-)

Comments

Laurent Pinchart June 10, 2021, 4:55 p.m. UTC | #1
Hi Ricardo,

Thank you for the patch.

On Fri, Mar 26, 2021 at 10:58:32AM +0100, Ricardo Ribalda wrote:
> We can figure out if reading/writing a set of controls can fail without

> accessing them by checking their flags.

> 

> This way we can honor the API closer:

> 

> If an error is found when validating the list of controls passed with

> VIDIOC_G_EXT_CTRLS, then error_idx shall be set to ctrls->count to

> indicate to userspace that no actual hardware was touched.

> 

> Fixes v4l2-compliance:

> Control ioctls (Input 0):

> 		warn: v4l2-test-controls.cpp(765): g_ext_ctrls(0) invalid error_idx 0

>                 fail: v4l2-test-controls.cpp(645): invalid error index write only control

>         test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL

> 

> Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>


Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>


> ---

>  drivers/media/usb/uvc/uvc_ctrl.c | 22 ++++++++++++++++++

>  drivers/media/usb/uvc/uvc_v4l2.c | 39 ++++++++++++++++++++++++++++----

>  drivers/media/usb/uvc/uvcvideo.h |  2 ++

>  3 files changed, 58 insertions(+), 5 deletions(-)

> 

> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c

> index 929e70dff11a..24fd5afc4e4f 100644

> --- a/drivers/media/usb/uvc/uvc_ctrl.c

> +++ b/drivers/media/usb/uvc/uvc_ctrl.c

> @@ -1046,6 +1046,28 @@ static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,

>  	return 0;

>  }

>  

> +int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,

> +			   bool read)

> +{

> +	struct uvc_control_mapping *mapping;

> +	struct uvc_control *ctrl;

> +

> +	if (__uvc_query_v4l2_class(chain, v4l2_id, 0) >= 0)

> +		return -EACCES;

> +

> +	ctrl = uvc_find_control(chain, v4l2_id, &mapping);

> +	if (!ctrl)

> +		return -EINVAL;

> +

> +	if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) && read)

> +		return -EACCES;

> +

> +	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read)

> +		return -EACCES;

> +

> +	return 0;

> +}

> +

>  static const char *uvc_map_get_name(const struct uvc_control_mapping *map)

>  {

>  	const char *name;

> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c

> index 28ccaa8b9e42..a3ee1dc003fc 100644

> --- a/drivers/media/usb/uvc/uvc_v4l2.c

> +++ b/drivers/media/usb/uvc/uvc_v4l2.c

> @@ -991,6 +991,26 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,

>  	return 0;

>  }

>  

> +static int uvc_ctrl_check_access(struct uvc_video_chain *chain,

> +				 struct v4l2_ext_controls *ctrls,

> +				 unsigned long ioctl)

> +{

> +	struct v4l2_ext_control *ctrl = ctrls->controls;

> +	unsigned int i;

> +	int ret = 0;

> +

> +	for (i = 0; i < ctrls->count; ++ctrl, ++i) {

> +		ret = uvc_ctrl_is_accessible(chain, ctrl->id,

> +					    ioctl == VIDIOC_G_EXT_CTRLS);

> +		if (ret)

> +			break;

> +	}

> +

> +	ctrls->error_idx = ioctl == VIDIOC_TRY_EXT_CTRLS ? i : ctrls->count;

> +

> +	return ret;

> +}

> +

>  static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,

>  				 struct v4l2_ext_controls *ctrls)

>  {

> @@ -1000,6 +1020,10 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,

>  	unsigned int i;

>  	int ret;

>  

> +	ret = uvc_ctrl_check_access(chain, ctrls, VIDIOC_G_EXT_CTRLS);

> +	if (ret < 0)

> +		return ret;

> +

>  	if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) {

>  		for (i = 0; i < ctrls->count; ++ctrl, ++i) {

>  			struct v4l2_queryctrl qc = { .id = ctrl->id };

> @@ -1036,13 +1060,17 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,

>  

>  static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,

>  				     struct v4l2_ext_controls *ctrls,

> -				     bool commit)

> +				     unsigned long ioctl)

>  {

>  	struct v4l2_ext_control *ctrl = ctrls->controls;

>  	struct uvc_video_chain *chain = handle->chain;

>  	unsigned int i;

>  	int ret;

>  

> +	ret = uvc_ctrl_check_access(chain, ctrls, ioctl);

> +	if (ret < 0)

> +		return ret;

> +

>  	ret = uvc_ctrl_begin(chain);

>  	if (ret < 0)

>  		return ret;

> @@ -1051,14 +1079,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,

>  		ret = uvc_ctrl_set(handle, ctrl);

>  		if (ret < 0) {

>  			uvc_ctrl_rollback(handle);

> -			ctrls->error_idx = commit ? ctrls->count : i;

> +			ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?

> +						    ctrls->count : i;

>  			return ret;

>  		}

>  	}

>  

>  	ctrls->error_idx = 0;

>  

> -	if (commit)

> +	if (ioctl == VIDIOC_S_EXT_CTRLS)

>  		return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count);

>  	else

>  		return uvc_ctrl_rollback(handle);

> @@ -1069,7 +1098,7 @@ static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,

>  {

>  	struct uvc_fh *handle = fh;

>  

> -	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, true);

> +	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_S_EXT_CTRLS);

>  }

>  

>  static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,

> @@ -1077,7 +1106,7 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,

>  {

>  	struct uvc_fh *handle = fh;

>  

> -	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, false);

> +	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);

>  }

>  

>  static int uvc_ioctl_querymenu(struct file *file, void *fh,

> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h

> index dc20021f7ee0..9471c342a310 100644

> --- a/drivers/media/usb/uvc/uvcvideo.h

> +++ b/drivers/media/usb/uvc/uvcvideo.h

> @@ -902,6 +902,8 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle)

>  

>  int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);

>  int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);

> +int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,

> +			   bool read);

>  

>  int uvc_xu_ctrl_query(struct uvc_video_chain *chain,

>  		      struct uvc_xu_control_query *xqry);


-- 
Regards,

Laurent Pinchart
diff mbox series

Patch

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 929e70dff11a..24fd5afc4e4f 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1046,6 +1046,28 @@  static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
 	return 0;
 }
 
+int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
+			   bool read)
+{
+	struct uvc_control_mapping *mapping;
+	struct uvc_control *ctrl;
+
+	if (__uvc_query_v4l2_class(chain, v4l2_id, 0) >= 0)
+		return -EACCES;
+
+	ctrl = uvc_find_control(chain, v4l2_id, &mapping);
+	if (!ctrl)
+		return -EINVAL;
+
+	if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) && read)
+		return -EACCES;
+
+	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read)
+		return -EACCES;
+
+	return 0;
+}
+
 static const char *uvc_map_get_name(const struct uvc_control_mapping *map)
 {
 	const char *name;
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 28ccaa8b9e42..a3ee1dc003fc 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -991,6 +991,26 @@  static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
 	return 0;
 }
 
+static int uvc_ctrl_check_access(struct uvc_video_chain *chain,
+				 struct v4l2_ext_controls *ctrls,
+				 unsigned long ioctl)
+{
+	struct v4l2_ext_control *ctrl = ctrls->controls;
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+		ret = uvc_ctrl_is_accessible(chain, ctrl->id,
+					    ioctl == VIDIOC_G_EXT_CTRLS);
+		if (ret)
+			break;
+	}
+
+	ctrls->error_idx = ioctl == VIDIOC_TRY_EXT_CTRLS ? i : ctrls->count;
+
+	return ret;
+}
+
 static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 				 struct v4l2_ext_controls *ctrls)
 {
@@ -1000,6 +1020,10 @@  static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 	unsigned int i;
 	int ret;
 
+	ret = uvc_ctrl_check_access(chain, ctrls, VIDIOC_G_EXT_CTRLS);
+	if (ret < 0)
+		return ret;
+
 	if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) {
 		for (i = 0; i < ctrls->count; ++ctrl, ++i) {
 			struct v4l2_queryctrl qc = { .id = ctrl->id };
@@ -1036,13 +1060,17 @@  static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 
 static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
 				     struct v4l2_ext_controls *ctrls,
-				     bool commit)
+				     unsigned long ioctl)
 {
 	struct v4l2_ext_control *ctrl = ctrls->controls;
 	struct uvc_video_chain *chain = handle->chain;
 	unsigned int i;
 	int ret;
 
+	ret = uvc_ctrl_check_access(chain, ctrls, ioctl);
+	if (ret < 0)
+		return ret;
+
 	ret = uvc_ctrl_begin(chain);
 	if (ret < 0)
 		return ret;
@@ -1051,14 +1079,15 @@  static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
 		ret = uvc_ctrl_set(handle, ctrl);
 		if (ret < 0) {
 			uvc_ctrl_rollback(handle);
-			ctrls->error_idx = commit ? ctrls->count : i;
+			ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
+						    ctrls->count : i;
 			return ret;
 		}
 	}
 
 	ctrls->error_idx = 0;
 
-	if (commit)
+	if (ioctl == VIDIOC_S_EXT_CTRLS)
 		return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count);
 	else
 		return uvc_ctrl_rollback(handle);
@@ -1069,7 +1098,7 @@  static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
 {
 	struct uvc_fh *handle = fh;
 
-	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, true);
+	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_S_EXT_CTRLS);
 }
 
 static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
@@ -1077,7 +1106,7 @@  static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
 {
 	struct uvc_fh *handle = fh;
 
-	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, false);
+	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
 }
 
 static int uvc_ioctl_querymenu(struct file *file, void *fh,
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index dc20021f7ee0..9471c342a310 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -902,6 +902,8 @@  static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
 
 int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);
 int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);
+int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
+			   bool read);
 
 int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
 		      struct uvc_xu_control_query *xqry);