On #14303, I shared unmodified files from our bug tracker corpus that appeared to cause some problems for pdf.js.  On this issue, I'll attach files that are freshly fuzzed using files from that corpus as seeds.  I avoided files used in #14303 as seeds for these runs  

I haven't done root cause analysis, and I apologize if these are all just triggering the same underlying bug (or that fixed in #14304).  The files are named for their seed file and then the sha-256 of the fuzzed version.

[new-nasties.zip](https://github.com/mozilla/pdf.js/files/7598083/new-nasties.zip)
const renderTask1 = page.render({
        canvasContext: canvasAndCtx.context,
        canvasFactory: CanvasFactory,
        viewport,
        optionalContentConfigPromise,
      });
      expect(renderTask1 instanceof RenderTask).toEqual(true);
      const renderTask2 = page.render({
        canvasContext: canvasAndCtx.context,
        canvasFactory: CanvasFactory,
        viewport,
        optionalContentConfigPromise,
      });
      expect(renderTask2 instanceof RenderTask).toEqual(true);
      await Promise.all([
        renderTask1.promise,
        renderTask2.promise.then(
          () => {
            
            expect(false).toEqual(true);
          
          reason => {
            // It fails because we are already using this canvas.
            .toEqual(true);
          }
        ),
      ]);
    });
    it("cleans up document resources after rendering of page", async function () {
      const loadingTask = getDocument(buildGetDocumentParams(basicApiFileName));