msm: camera: cpp: Add validation for v4l2 ioctl arguments

In CPP v4l2 ioctl command is made, if _IOC_DIR(cmd) is
_IOC_NONE, then the user-supplied argument arg is not checked
and an information disclosure is possible
CRs-Fixed: 1042068

Change-Id: Iddb291b10cdcb5c42ab8497e06c2ce47885cd5ab
Signed-off-by: Suman Mukherjee <sumam@codeaurora.org>
Signed-off-by: Sunid Wilson <sunidw@codeaurora.org>

drivers/media/platform/msm/camera_v2/pproc/cpp/msm_cpp.c

@@ -1537,7 +1537,10 @@ long msm_cpp_subdev_ioctl(struct v4l2_subdev *sd,
 		pr_err("cpp_dev is null\n");
 		return -EINVAL;
 	}
-
+	if (_IOC_DIR(cmd) == _IOC_NONE) {
+		pr_err("Invalid ioctl/subdev cmd %u", cmd);
+		return -EINVAL;
+	}
 	if ((ioctl_ptr->ioctl_ptr == NULL) || (ioctl_ptr->len == 0)) {
 		pr_err("ioctl_ptr OR ioctl_ptr->len is NULL  %p %d\n",
 			ioctl_ptr, ioctl_ptr->len);