harfbuzz

History

Ebrahim Byagowi 758fda728b [glyf] Don't accept gids higher than maxp's glyphs number This specially becomes concerning on sub-components where a gvar table that is sanitized using maxp's glyphs number overflows when a high gid accepted here goes to it, maybe an additional check can be put there also, this however feels to be enough. Fixes https://crbug.com/oss-fuzz/20944		2020-02-28 23:19:06 +03:30
..
fonts	[glyf] Don't accept gids higher than maxp's glyphs number	2020-02-28 23:19:06 +03:30
sets	[fuzz] minor, move two fuzzer cases to their correct place	2020-02-12 19:17:18 +03:30
CMakeLists.txt	Remove remains of get-codepoint-fuzzer	2018-10-11 17:31:29 -04:00
hb-draw-fuzzer.cc	minor	2020-02-26 16:36:48 +03:30
hb-fuzzer.hh	[fuzzer] Separate main() into a new file	2016-12-20 20:50:38 -06:00
hb-set-fuzzer.cc	[fuzz] minor style fixes	2020-02-12 19:30:31 +03:30
hb-shape-fuzzer.cc	[fuzz] Practice variations on font object	2020-02-25 21:16:57 +03:30
hb-subset-fuzzer.cc	[fuzz] Don't fail when blob is empty	2019-07-11 14:31:55 +04:30
main.cc	[fuzz] minor don't abort main.cc when the file was empty or not found	2020-02-26 16:15:17 +03:30
Makefile.am	[draw] Add fuzzer runner	2020-02-28 19:57:56 +03:30
README	Move all references of old url to the new address (#622 )	2017-11-20 14:49:22 -05:00
run-draw-fuzzer-tests.py	[draw] Add fuzzer runner	2020-02-28 19:57:56 +03:30
run-shape-fuzzer-tests.py	Remove python2 support from tests/utils scripts	2020-02-19 16:17:45 +03:30
run-subset-fuzzer-tests.py	Remove python2 support from tests/utils scripts	2020-02-19 16:17:45 +03:30

README

In order to build the fuzzer one needs to build HarfBuzz and
harfbuzz/test/fuzzing/hb-fuzzer.cc with:
  - Using the most recent Clang
  - With -fsanitize=address (or =undefined, or a combination)
  - With -fsanitize-coverage=edge[,8bit-counters,trace-cmp]
  - With various defines that limit worst case exponential behavior.
    See FUZZING_CPPFLAGS in harfbuzz/src/Makefile.am for the list.
  - link against libFuzzer

To run the fuzzer one needs to first obtain a test corpus as a directory
containing interesting fonts.  A good starting point is inside
harfbuzz/test/shaping/fonts/fonts/.
Then, run the fuzzer like this:
   ./hb-fuzzer -max_len=2048 CORPUS_DIR
Where max_len specifies the maximal length of font files to handle.
The smaller the faster.

For more details consult the following locations:
  - http://llvm.org/docs/LibFuzzer.html or
  - https://github.com/google/libfuzzer-bot/tree/master/harfbuzz
  - https://github.com/harfbuzz/harfbuzz/issues/139