[PATCH 5.15 031/917] media: v4l2-ioctl: Fix check_ext_ctrls

Greg Kroah-Hartman
2021-11-16T01:14:26Z

From: Ricardo Ribalda <ribalda@chromium.org>

commit 861f92cb9160b14beef0ada047384c2340701ee2 upstream.

Drivers that do not use the ctrl-framework use this function instead.

Fix the following issues:

- Do not check for multiple classes when getting the DEF_VAL.
- Return -EINVAL for request_api calls
- Default value cannot be changed, return EINVAL as soon as possible.
- Return the right error_idx
[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.
It would have been much nicer of course if error_idx could point to the
control index that failed the validation, but sadly that's not how the
API was designed.]

Fixes v4l2-compliance:
Control ioctls (Input 0):
warn: v4l2-test-controls.cpp(834): error_idx should be equal to count
warn: v4l2-test-controls.cpp(855): error_idx should be equal to count
fail: v4l2-test-controls.cpp(813): doioctl(node, VIDIOC_G_EXT_CTRLS, &ctrls)
test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL
Buffer ioctls (Input 0):
fail: v4l2-test-buffers.cpp(1994): ret != EINVAL && ret != EBADR && ret != ENOTTY
test Requests: FAIL

Cc: stable@vger.kernel.org
Fixes: 6fa6f831f095 ("media: v4l2-ctrls: add core request support")
Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/media/v4l2-core/v4l2-ioctl.c | 60 ++++++++++++++++++++++-------------
1 file changed, 39 insertions(+), 21 deletions(-)

--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -869,7 +869,7 @@ static void v4l_print_default(const void
pr_cont("driver-specific ioctl\n");
}

-static int check_ext_ctrls(struct v4l2_ext_controls *c, int allow_priv)
+static bool check_ext_ctrls(struct v4l2_ext_controls *c, unsigned long ioctl)
{
__u32 i;

@@ -878,23 +878,41 @@ static int check_ext_ctrls(struct v4l2_e
for (i = 0; i < c->count; i++)
c->controls[i].reserved2[0] = 0;

- /* V4L2_CID_PRIVATE_BASE cannot be used as control class
- when using extended controls.
- Only when passed in through VIDIOC_G_CTRL and VIDIOC_S_CTRL
- is it allowed for backwards compatibility.
- */
- if (!allow_priv && c->which == V4L2_CID_PRIVATE_BASE)
- return 0;
- if (!c->which)
- return 1;
+ switch (c->which) {
+ case V4L2_CID_PRIVATE_BASE:
+ /*
+ * V4L2_CID_PRIVATE_BASE cannot be used as control class
+ * when using extended controls.
+ * Only when passed in through VIDIOC_G_CTRL and VIDIOC_S_CTRL
+ * is it allowed for backwards compatibility.
+ */
+ if (ioctl == VIDIOC_G_CTRL || ioctl == VIDIOC_S_CTRL)
+ return false;
+ break;
+ case V4L2_CTRL_WHICH_DEF_VAL:
+ /* Default value cannot be changed */
+ if (ioctl == VIDIOC_S_EXT_CTRLS ||
+ ioctl == VIDIOC_TRY_EXT_CTRLS) {
+ c->error_idx = c->count;
+ return false;
+ }
+ return true;
+ case V4L2_CTRL_WHICH_CUR_VAL:
+ return true;
+ case V4L2_CTRL_WHICH_REQUEST_VAL:
+ c->error_idx = c->count;
+ return false;
+ }
+
/* Check that all controls are from the same control class. */
for (i = 0; i < c->count; i++) {
if (V4L2_CTRL_ID2WHICH(c->controls[i].id) != c->which) {
- c->error_idx = i;
- return 0;
+ c->error_idx = ioctl == VIDIOC_TRY_EXT_CTRLS ? i :
+ c->count;
+ return false;
}
}
- return 1;
+ return true;
}

static int check_fmt(struct file *file, enum v4l2_buf_type type)
@@ -2187,7 +2205,7 @@ static int v4l_g_ctrl(const struct v4l2_
ctrls.controls = &ctrl;
ctrl.id = p->id;
ctrl.value = p->value;
- if (check_ext_ctrls(&ctrls, 1)) {
+ if (check_ext_ctrls(&ctrls, VIDIOC_G_CTRL)) {
int ret = ops->vidioc_g_ext_ctrls(file, fh, &ctrls);

if (ret == 0)
@@ -2221,7 +2239,7 @@ static int v4l_s_ctrl(const struct v4l2_
ctrls.controls = &ctrl;
ctrl.id = p->id;
ctrl.value = p->value;
- if (check_ext_ctrls(&ctrls, 1))
+ if (check_ext_ctrls(&ctrls, VIDIOC_S_CTRL))
return ops->vidioc_s_ext_ctrls(file, fh, &ctrls);
return -EINVAL;
}
@@ -2243,8 +2261,8 @@ static int v4l_g_ext_ctrls(const struct
vfd, vfd->v4l2_dev->mdev, p);
if (ops->vidioc_g_ext_ctrls == NULL)
return -ENOTTY;
- return check_ext_ctrls(p, 0) ? ops->vidioc_g_ext_ctrls(file, fh, p) :
- -EINVAL;
+ return check_ext_ctrls(p, VIDIOC_G_EXT_CTRLS) ?
+ ops->vidioc_g_ext_ctrls(file, fh, p) : -EINVAL;
}

static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops,
@@ -2264,8 +2282,8 @@ static int v4l_s_ext_ctrls(const struct
vfd, vfd->v4l2_dev->mdev, p);
if (ops->vidioc_s_ext_ctrls == NULL)
return -ENOTTY;
- return check_ext_ctrls(p, 0) ? ops->vidioc_s_ext_ctrls(file, fh, p) :
- -EINVAL;
+ return check_ext_ctrls(p, VIDIOC_S_EXT_CTRLS) ?
+ ops->vidioc_s_ext_ctrls(file, fh, p) : -EINVAL;
}

static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops,
@@ -2285,8 +2303,8 @@ static int v4l_try_ext_ctrls(const struc
vfd, vfd->v4l2_dev->mdev, p);
if (ops->vidioc_try_ext_ctrls == NULL)
return -ENOTTY;
- return check_ext_ctrls(p, 0) ? ops->vidioc_try_ext_ctrls(file, fh, p) :
- -EINVAL;
+ return check_ext_ctrls(p, VIDIOC_TRY_EXT_CTRLS) ?
+ ops->vidioc_try_ext_ctrls(file, fh, p) : -EINVAL;
}

/*