8027252: Crash in interpreter because get_unsigned_2_byte_index_at_bcp reads 4 bytes

Summary: Use 2-byte loads to load indexes from the byte code stream to avoid out of bounds reads.
Reviewed-by: coleenp, sspitsyn

1 files changed, 1 insertions, 1 deletions

diff --git a/src/cpu/x86/vm/interp_masm_x86_64.cpp b/src/cpu/x86/vm/interp_masm_x86_64.cpp
index 7758d8fbc..520c872a6 100644
--- a/src/cpu/x86/vm/interp_masm_x86_64.cpp
+++ b/src/cpu/x86/vm/interp_masm_x86_64.cpp
@@ -192,7 +192,7 @@ void InterpreterMacroAssembler::get_unsigned_2_byte_index_at_bcp(
   Register reg,
   int bcp_offset) {
   assert(bcp_offset >= 0, "bcp is still pointing to start of bytecode");
-  movl(reg, Address(r13, bcp_offset));
+  load_unsigned_short(reg, Address(r13, bcp_offset));
   bswapl(reg);
   shrl(reg, 16);
 }