media: rcar_drif: fix a memory disclosure

hulk inclusion
category: bugfix
bugzilla: 13690
CVE: CVE-2019-18786

-------------------------------------------------

"f->fmt.sdr.reserved" is uninitialized. As other peer drivers
like msi2500 and airspy do, the fix initializes it to avoid
memory disclosures.
Signed-off-by: NKangjie Lu <kjlu@umn.edu>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NWenan Mao <maowenan@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/media/platform/rcar_drif.c

@@ -912,6 +912,7 @@ static int rcar_drif_g_fmt_sdr_cap(struct file *file, void *priv,
 {
 	struct rcar_drif_sdr *sdr = video_drvdata(file);
 
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 	f->fmt.sdr.pixelformat = sdr->fmt->pixelformat;
 	f->fmt.sdr.buffersize = sdr->fmt->buffersize;