Files
pdfcraft/vendor/lopdf/examples/verify_pdf.rs
Brandon ThomasandClaude Opus 5.5 1449b71a19 Never crash: bound the allocations behind the nightly fuzz runner's out-of-memory deaths
Fuzzed inputs drove one check-one process to 2-6 GB (the 16 GB CI runner
running two of them was killed every night). Three causes, each with a test:
- lopdf (bootstrap inspector) sized PNG predictor rows from /Columns before
  reading data: /Columns 4294967295 allocated two 4 GiB rows. Vendored lopdf
  0.45.0 refuses rows longer than the data (and uses saturating row widths);
  its load-time stream decoding also gets a 256 MiB limit (it had none).
- hayro sized a tiling pattern's cell pixmap from /XStep x scale, bounded only
  by u16: a step far beyond /BBox allocated 2 GB. The vendored patch keeps
  the cell within 3000 px a side, lowering the resolution instead.
- cos decoded cross-reference streams up to the general 1 GiB limit; they now
  stop at what 8,388,607 objects' rows can hold (~200 MB at most), and the
  section is reconstructed (logged) instead.

On the nightly's seed (41) the worst captured input fell from 6.2 GB to 6 MB,
and a 300 s fuzz run had no process above 300 MB (before: many at 2-5 GB).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 17:59:25 -04:00

65 lines
1.8 KiB
Rust

use lopdf::{Document, Object};
use std::env;
#[cfg(feature = "async")]
use tokio::runtime::Builder;
#[cfg(not(feature = "async"))]
fn load_document(path: &str) -> Result<Document, lopdf::Error> {
Document::load(path)
}
#[cfg(feature = "async")]
fn load_document(path: &str) -> Result<Document, lopdf::Error> {
Builder::new_current_thread()
.enable_all()
.build()
.unwrap()
.block_on(async move { Document::load(path).await })
}
fn main() {
let args: Vec<String> = env::args().collect();
if args.len() < 2 {
eprintln!("Usage: {} <pdf_file>", args[0]);
std::process::exit(1);
}
let pdf_path = &args[1];
println!("Verifying PDF: {}", pdf_path);
match load_document(pdf_path) {
Ok(doc) => {
println!("✓ PDF loaded successfully");
println!(" Version: {:?}", doc.version);
println!(" Objects: {}", doc.objects.len());
// Count pages
let pages = doc.get_pages();
println!(" Pages: {}", pages.len());
// Check for object streams
let mut obj_stream_count = 0;
for obj in doc.objects.values() {
if let Object::Stream(stream) = obj
&& let Ok(type_obj) = stream.dict.get(b"Type")
&& let Ok(type_name) = type_obj.as_name()
&& type_name == b"ObjStm"
{
obj_stream_count += 1;
}
}
if obj_stream_count > 0 {
println!(" Object streams: {}", obj_stream_count);
}
println!("\nPDF is valid and can be opened!");
}
Err(e) => {
eprintln!("✗ Failed to load PDF: {}", e);
std::process::exit(1);
}
}
}