[libldac] Disable MSan

[posidron]

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12298

[inferno-chromium]

@posidron - UBSan has a startup crash as well and is blocking build. Can you get it fixed in fuzzer or underlying code OR otherwise disable ubsan as well. ?

Step #13: Base64: Cg== I
Step #13: artifact_prefix='./'; Test unit written to ./crash-adc83b19e793491b1c6ea0fd8b46cd9f32e592fc I
Step #13: \x0a I
Step #13: 0xa, I
Step #13: MS: 0 ; base unit: 0000000000000000000000000000000000000000 I
Step #13: SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior src/pack_ldac.c:35:18 in I
Step #13: I
Step #13: #14 0x405d18 in _start (out/undefined/libldac_encode_fuzzer+0x405d18) I
Step #13: #13 0x7f519859b82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f) I
Step #13: #12 0x4314d8 in main /src/libfuzzer/FuzzerMain.cpp:20:10 I
Step #13: #11 0x4355d3 in fuzzer::FuzzerDriver(int*, char***, int ()(unsigned char const, unsigned long)) /src/libfuzzer/FuzzerDriver.cpp:764:6 I
Step #13: #10 0x442f65 in fuzzer::Fuzzer::Loop(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, fuzzer::fuzzer_allocator<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > > > const&) /src/libfuzzer/FuzzerLoop.cpp:806:3 I
Step #13: #9 0x442b0c in fuzzer::Fuzzer::ReadAndExecuteSeedCorpora(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, fuzzer::fuzzer_allocator<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator > > > const&) /src/libfuzzer/FuzzerLoop.cpp:766:5 I
Step #13: #8 0x440595 in fuzzer::Fuzzer::RunOne(unsigned char const*, unsigned long, bool, fuzzer::InputInfo*, bool*) /src/libfuzzer/FuzzerLoop.cpp:480:3 I
Step #13: #7 0x4411c8 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) /src/libfuzzer/FuzzerLoop.cpp:571:15 I
Step #13: #6 0x464535 in LLVMFuzzerTestOneInput /src/libldac_encode_fuzzer.cc:31:5 I
Step #13: #5 0x46ffd4 in ldacBT_encode /src/libldac/src/ldacBT_api.c:550:18 I
Step #13: #4 0x466250 in ldaclib_encode /src/libldac/src/ldaclib_api.c:710:18 I
Step #13: #3 0x46705f in pack_raw_data_frame_ldac /src/libldac/src/pack_ldac.c:434:14 I
Step #13: #2 0x468349 in pack_audio_block_ldac /src/libldac/src/pack_ldac.c:397:9 I
Step #13: #1 0x468b19 in pack_spectrum_ldac /src/libldac/src/pack_ldac.c:322:17 I
Step #13: #0 0x4681e6 in pack_store_ldac /src/libldac/src/pack_ldac.c:35:18 I
Step #13: src/pack_ldac.c:35:18: runtime error: left shift of negative value -225 I
Step #13: INFO: A corpus is not provided, starting from an empty corpus I
Step #13: INFO: -max_len is not provided; libFuzzer will not generate inputs larger than 4096 bytes I
Step #13: INFO: Loaded 1 PC tables (962 PCs): 962 [0x504180,0x507da0), I
Step #13: INFO: Loaded 1 modules (962 inline 8-bit counters): 962 [0x74af60, 0x74b322), I
Step #13: INFO: Seed: 1950751695 I
Step #13: BAD BUILD: /workspace/out/undefined/libldac_encode_fuzzer seems to have either startup crash or exit: I

[posidron]

@inferno-chromium I will disable it too. Sorry, wasn't aware that those would be interpreted as build errors.

[inferno-chromium]

@posidron - yes we expect fuzzers to work in a basic fashion, otherwise they just eat up fuzzing cycles and also such failure usually break regression testing. like if a new startup crash sneaks in and we archive that build, then regression testing will be broken for future testcases since the range it gives will be bad_revision:something

[posidron]

Yea. No it makes totally sense. Nevermind. :)