[PATCH v2] media: imx: Fix NULL pointer dereference

[Siddarth G <siddarthsgml@gmail.com>]

Cppcheck warnings:

drivers/staging/media/imx/imx-media-fim.c:79:6:
error: Null pointer dereference: fi [ctunullpointer]
  if (fi->denominator == 0) {

drivers/staging/media/imx/imx-media-csi.c:795:27:
note: Calling function imx_media_fim_set_stream, 2nd argument is null
  imx_media_fim_set_stream(priv->fim, NULL, false);

drivers/staging/media/imx/imx-media-fim.c:388:3:
note: Calling function update_fim_nominal, 2nd argument is null
  update_fim_nominal(fim, fi);

drivers/staging/media/imx/imx-media-fim.c:79:6:
note: Dereferencing argument fi that is null
  if (fi->denominator == 0) {

To fix the issue, add a check to validate that the 'fi' is not
null before accessing its members.

Signed-off-by: Siddarth G <siddarthsgml@gmail.com>
---
Changes since v1:
- added "media:" prefix in subject

 drivers/staging/media/imx/imx-media-fim.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/media/imx/imx-media-fim.c b/drivers/staging/media/imx/imx-media-fim.c
index ccbc0371fba2..25f79d0f87b9 100644
--- a/drivers/staging/media/imx/imx-media-fim.c
+++ b/drivers/staging/media/imx/imx-media-fim.c
@@ -76,6 +76,9 @@ static bool icap_enabled(struct imx_media_fim *fim)
 static void update_fim_nominal(struct imx_media_fim *fim,
 			       const struct v4l2_fract *fi)
 {
+	if (!fi)
+		return;
+
 	if (fi->denominator == 0) {
 		dev_dbg(fim->sd->dev, "no frame interval, FIM disabled\n");
 		fim->enabled = false;
-- 
2.43.0