[PATCH AUTOSEL 5.7 014/274] media: v4l2-ctrls: v4l2_ctrl_g/s_ctrl*(): don't continue when WARN_ON

Sasha Levin
2020-06-09T01:09:40Z

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

[ Upstream commit 7c3bae3f430af6b4fcbdb7272e191e266fd94b45 ]

If the v4l2_ctrl_g_ctrl*() or __v4l2_ctrl_s_ctrl*() functions
are called for the wrong control type then they call WARN_ON
since that is a driver error. But they still continue, potentially
overwriting data. Change this to return an error (s_ctrl) or 0
(g_ctrl), just to be safe.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/v4l2-core/v4l2-ctrls.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 93d33d1db4e8..452edd06d67d 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3794,7 +3794,8 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl)
struct v4l2_ext_control c;

/* It's a driver bug if this happens. */
- WARN_ON(!ctrl->is_int);
+ if (WARN_ON(!ctrl->is_int))
+ return 0;
c.value = 0;
get_ctrl(ctrl, &c);
return c.value;
@@ -3806,7 +3807,8 @@ s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl)
struct v4l2_ext_control c;

/* It's a driver bug if this happens. */
- WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64);
+ if (WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64))
+ return 0;
c.value64 = 0;
get_ctrl(ctrl, &c);
return c.value64;
@@ -4215,7 +4217,8 @@ int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
lockdep_assert_held(ctrl->handler->lock);

/* It's a driver bug if this happens. */
- WARN_ON(!ctrl->is_int);
+ if (WARN_ON(!ctrl->is_int))
+ return -EINVAL;
ctrl->val = val;
return set_ctrl(NULL, ctrl, 0);
}
@@ -4226,7 +4229,8 @@ int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
lockdep_assert_held(ctrl->handler->lock);

/* It's a driver bug if this happens. */
- WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64);
+ if (WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64))
+ return -EINVAL;
*ctrl->p_new.p_s64 = val;
return set_ctrl(NULL, ctrl, 0);
}
@@ -4237,7 +4241,8 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
lockdep_assert_held(ctrl->handler->lock);

/* It's a driver bug if this happens. */
- WARN_ON(ctrl->type != V4L2_CTRL_TYPE_STRING);
+ if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_STRING))
+ return -EINVAL;
strscpy(ctrl->p_new.p_char, s, ctrl->maximum + 1);
return set_ctrl(NULL, ctrl, 0);
}
@@ -4249,7 +4254,8 @@ int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
lockdep_assert_held(ctrl->handler->lock);

/* It's a driver bug if this happens. */
- WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA);
+ if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA))
+ return -EINVAL;
*ctrl->p_new.p_area = *area;
return set_ctrl(NULL, ctrl, 0);
}
--
2.25.1