mtd: mtdchar: fix information leak to userland

Structure mtd_info_user is copied to userland with padding byted
between "type" and "flags" fields uninitialized.  It leads to leaking
of contents of kernel stack memory.
Signed-off-by: NVasiliy Kulikov <segooon@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdchar.c

@@ -601,6 +601,7 @@ static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 	}
 
 	case MEMGETINFO:
+		memset(&info, 0, sizeof(info));
 		info.type	= mtd->type;
 		info.flags	= mtd->flags;
 		info.size	= mtd->size;
@@ -609,7 +610,6 @@ static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 		info.oobsize	= mtd->oobsize;
 		/* The below fields are obsolete */
 		info.ecctype	= -1;
-		info.eccsize	= 0;
 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 			return -EFAULT;
 		break;