Files
pdfcraft/vendor/lopdf/src/content.rs
T
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

47 lines
1.2 KiB
Rust

use super::Object;
use crate::Result;
use crate::writer::Writer;
use std::io::Write;
#[derive(Debug, Clone)]
pub struct Operation {
pub operator: String,
pub operands: Vec<Object>,
}
impl Operation {
pub fn new(operator: &str, operands: Vec<Object>) -> Operation {
Operation {
operator: operator.to_string(),
operands,
}
}
}
#[derive(Debug, Clone)]
pub struct Content<Operations: AsRef<[Operation]> = Vec<Operation>> {
pub operations: Operations,
}
impl<Operations: AsRef<[Operation]>> Content<Operations> {
/// Encode content operations.
pub fn encode(&self) -> Result<Vec<u8>> {
let mut buffer = Vec::new();
let mut first_operation = true;
for operation in self.operations.as_ref() {
// Add new line after each operation except the last one.
if first_operation {
first_operation = false;
} else {
buffer.write_all(b"\n")?;
}
for operand in &operation.operands {
Writer::write_object(&mut buffer, operand)?;
buffer.write_all(b" ")?;
}
buffer.write_all(operation.operator.as_bytes())?;
}
Ok(buffer)
}
}