[PDFBOX-5781] OutOfMemoryError in FileSystemFontsProvider.scanFonts

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.30, 3.0.1 PDFBox
• Fix Version/s: 2.0.31, 3.0.2 PDFBox, 4.0.0
• Component/s: FontBox

Environment

Running inside a JVM with -Xmx512
openjdk version "17.0.10" 2024-01-16 LTS
OpenJDK Runtime Environment (build 17.0.10+13-LTS)
OpenJDK 64-Bit Server VM (build 17.0.10+13-LTS, mixed mode, sharing)
macOS Sonoma 14.3.1 (23D60)

• Assignee: Tilman Hausherr
• Reporter: Kim Hage
• Created: 07/Mar/24 16:34
• Updated: 14/Mar/24 20:57
• Resolved: 08/Mar/24 10:15

Description

We experienced an OutOfMemoryError when calling
PDAcroForm.getDefaultResources().getFont(COSName); with COSName{Helv}

The reason seemed to be that PdfBox initializes a FontCache when getFont is called and this scans all fonts on the system. This also loads some large system fonts (AppleColorEmoji is 189,9MB). Each font gets copied into a single large byte array at the location below and this causes an OutOfMemoryError at this point in the code.

org.apache.pdfbox.pdmodel.font.FileSystemFontProvider#addTrueTypeFontImpl:773

InputStream is = ttf.getOriginalData();
byte[] ba = IOUtils.toByteArray(is);
is.close();
String hash = computeHash(ba); 

I think this would be easily fixed by using a DigestInputStream instead of a byte array to compute hashes at this location. I have tested this locally and it seemed to work. Please see the attached .patch file