As detected by Coverity, the error check logic at get_ctrl() is
broken: if ptr_to_user() fails to fill a control due to an error,
no errors are returned and v4l2_g_ctrl() returns success on a
failed operation, which may cause applications to fail.
Add an error check at get_ctrl() and ensure that it will
be returned to userspace without filling the control value if
get_ctrl() fails.
Fixes: 71c689dc2e73 ("media: v4l2-ctrls: split up into four source files")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-ctrls-api.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c
index e5a364efd5e6..a0de7eeaf085 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-api.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c
@@ -753,9 +753,10 @@ static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
for (i = 0; i < master->ncontrols; i++)
cur_to_new(master->cluster[i]);
ret = call_op(master, g_volatile_ctrl);
- new_to_user(c, ctrl);
+ if (!ret)
+ ret = new_to_user(c, ctrl);
} else {
- cur_to_user(c, ctrl);
+ ret = cur_to_user(c, ctrl);
}
v4l2_ctrl_unlock(master);
return ret;
@@ -770,7 +771,10 @@ int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *control)
if (!ctrl || !ctrl->is_int)
return -EINVAL;
ret = get_ctrl(ctrl, &c);
- control->value = c.value;
+
+ if (!ret)
+ control->value = c.value;
+
return ret;
}
EXPORT_SYMBOL(v4l2_g_ctrl);
@@ -811,10 +815,12 @@ static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,
int ret;
v4l2_ctrl_lock(ctrl);
- user_to_new(c, ctrl);
+ ret = user_to_new(c, ctrl);
+ if (ret)
+ return ret;
ret = set_ctrl(fh, ctrl, 0);
if (!ret)
- cur_to_user(c, ctrl);
+ ret = cur_to_user(c, ctrl);
v4l2_ctrl_unlock(ctrl);
return ret;
}
--
2.47.0
