Replace the assert in mel_init to an if statement to address an issue with fuzzing. #1436
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… statement, returning false when an incorrect sequence of bytes are encountered in the MEL segment. Similar code should be added to the main MEL decoding subrountine, but the change is more involved; in any case, an incorrect sequence produces incorrect results, but should not be harmful or cause a crash.
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thanks. sorry for the delay! |
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Cherrypick the fix [1] from upstream OpenJPEG. [1] uclouvain/openjpeg#1436 Bug: chromium:1343737 Change-Id: Ie92a9b8b81dc105df8aa8159480d2f0ba0ccc569 Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/96471 Reviewed-by: Tom Sepez <[email protected]> Commit-Queue: Lei Zhang <[email protected]>
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Hi Even, Everyone,
This is to address the issue with the Fuzzer in
https://bugs.chromium.org/p/chromium/issues/detail?id=1343737
A wrong sequence should produce erroneous result, but should not cause a crash.
A similar if statement can be added to mel_read(), but this requires more changes -- no fuzzing issue produced for this.
I tried to run openjpeg fuzzing, but I did not know how to tell oss-fuzz what source to use. I tried
python infra/helper.py build_fuzzers --architecture x86_64 --sanitizer address openjpeg ~/openjpegThe first time, it ran with an error message at the end about conformance.
The second time, it is producing an error
mkdir: cannot create directory 'build': File exists, but I do not know where this folder is to delete it.I am happy to run fuzzing on this pull request.
Kind regards,
Aous.
PS: There is another small modification, unrelated to Chromium fuzzer, to some quantities to make them more meaningful, but let's get this thing through.