OSV-2020-789 Heap-use-after-free in llvm_ks::X86Operand::getToken

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22850 Crash type: Heap-use-after-free READ 4 Crash state: llvmks::X86Operand::getToken X86AsmParser::MatchAndEmitATTInstruction X86AsmParser::MatchAndEmitInstruction...

keystone/fuzz_asm_x86_64: Bad-cast to llvm_ks::X86OperandX86AsmParser::MatchAndEmitATTInstruction in AsmParser::parseStatement

Detailed report: https://oss-fuzz.com/testcase?key=5121855985287168 Project: keystone Fuzzer: libFuzzerkeystonefuzzasmx8664 Fuzz target binary: fuzzasmx8664 Job Type: libfuzzerubsankeystone Platform Id: linux Crash Type: Bad-cast Crash Address: 0x00000210d120 Crash State: Bad-cast to...