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From: Ricardo Ribalda <ribalda@chromium.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	tfiga@chromium.org
Cc: Ricardo Ribalda <ribalda@chromium.org>
Subject: [PATCH v10 14/21] media: uvcvideo: Check controls flags before accessing them
Date: Fri, 18 Jun 2021 14:29:16 +0200	[thread overview]
Message-ID: <20210618122923.385938-15-ribalda@chromium.org> (raw)
In-Reply-To: <20210618122923.385938-1-ribalda@chromium.org>

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

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 2cc2ff0d0cae..18c315b52ef5 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1042,6 +1042,28 @@ 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 b044d9455b2c..4aa78591d9b0 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -901,6 +901,8 @@ 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);
-- 
2.32.0.288.g62a8d224e6-goog


  parent reply	other threads:[~2021-06-18 12:30 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-18 12:29 [PATCH v10 00/21] Fix v4l2-compliance errors Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 01/21] media: v4l2-ioctl: Fix check_ext_ctrls Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 02/21] media: pvrusb2: Do not check for V4L2_CTRL_WHICH_DEF_VAL Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 03/21] media: uvcvideo: " Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 04/21] media: v4l2-ioctl: S_CTRL output the right value Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 05/21] media: uvcvideo: Remove s_ctrl and g_ctrl Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 06/21] media: uvcvideo: Set capability in s_param Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 07/21] media: uvcvideo: Return -EIO for control errors Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 08/21] media: uvcvideo: refactor __uvc_ctrl_add_mapping Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 09/21] media: uvcvideo: Add support for V4L2_CTRL_TYPE_CTRL_CLASS Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 10/21] media: uvcvideo: Use dev->name for querycap() Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 11/21] media: uvcvideo: Set unique vdev name based in type Ricardo Ribalda
2021-12-06 19:05   ` [REGRESSION] " Nicolas Dufresne
2021-12-06 19:15     ` Laurent Pinchart
2021-06-18 12:29 ` [PATCH v10 12/21] media: uvcvideo: Increase the size of UVC_METADATA_BUF_SIZE Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 13/21] media: uvcvideo: Use control names from framework Ricardo Ribalda
2021-09-03 10:10   ` Mauro Carvalho Chehab
2021-09-03 10:33     ` Ricardo Ribalda
2021-06-18 12:29 ` Ricardo Ribalda [this message]
2021-06-18 12:29 ` [PATCH v10 15/21] media: uvcvideo: Set error_idx during ctrl_commit errors Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 16/21] media: docs: Document the behaviour of uvcvideo driver Ricardo Ribalda
2021-06-18 12:29 ` [PATCH v10 17/21] uvcvideo: uvc_ctrl_is_accessible: check for INACTIVE Ricardo Ribalda
2021-08-22 23:40   ` Laurent Pinchart
2021-06-18 12:29 ` [PATCH v10 18/21] uvcvideo: improve error handling in uvc_query_ctrl() Ricardo Ribalda
2021-08-22 23:52   ` Laurent Pinchart
2021-06-18 12:29 ` [PATCH v10 19/21] uvcvideo: don't spam the log in uvc_ctrl_restore_values() Ricardo Ribalda
2021-08-22 23:23   ` Laurent Pinchart
2021-08-23  0:17   ` Laurent Pinchart
2021-08-23  7:32     ` Hans Verkuil
2021-06-18 12:29 ` [PATCH v10 20/21] uvc: use vb2 ioctl and fop helpers Ricardo Ribalda
2021-08-23  0:00   ` Laurent Pinchart
2021-06-18 12:29 ` [PATCH v10 21/21] media: uvcvideo: Return -EACCES to inactive controls Ricardo Ribalda
2021-06-25 10:29   ` Ricardo Ribalda
2021-06-25 11:06     ` Hans Verkuil
2021-06-25 13:55       ` Ricardo Ribalda
2021-06-30  9:02         ` Hans Verkuil
2021-06-30 12:51           ` Ricardo Ribalda
2021-07-06 14:18             ` Hans Verkuil
2021-07-07  9:07               ` Ricardo Ribalda

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