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media: uvcvideo: Check controls flags before accessing them

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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>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Ricardo Ribalda 2021-06-18 14:29:16 +02:00 committed by Mauro Carvalho Chehab
parent 70fa906d6f
commit ee929d5a10
3 changed files with 58 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/media/usb/uvc/uvc_ctrl.c
View File

@ -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;

39
drivers/media/usb/uvc/uvc_v4l2.c
View File

@ -1003,6 +1003,26 @@ 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)
{
@ -1012,6 +1032,10 @@ 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 };
@ -1048,13 +1072,17 @@ 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;
@ -1063,14 +1091,15 @@ 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);
@ -1081,7 +1110,7 @@ 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,
@ -1089,7 +1118,7 @@ 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,

2
drivers/media/usb/uvc/uvcvideo.h
View File

@ -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);