[Lldb-commits] [lldb] r362510 - [lldb] Fix out-of-bounds read after c3ea7c66fec021867e005ad1b02f3c7e80feaa85

[James Y Knight via lldb-commits]

Author: jyknight
Date: Tue Jun  4 08:27:19 2019
New Revision: 362510

URL: http://llvm.org/viewvc/llvm-project?rev=362510&view=rev
Log:
[lldb] Fix out-of-bounds read after c3ea7c66fec021867e005ad1b02f3c7e80feaa85
"Add support for mid-function epilogues on x86 that end in a non-local jump."

Detected by asan.

Modified:
    lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp

Modified: lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp?rev=362510&r1=362509&r2=362510&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp (original)
+++ lldb/trunk/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp Tue Jun  4 08:27:19 2019
@@ -736,7 +736,6 @@ bool x86AssemblyInspectionEngine::pc_rel
   int opcode_size = 0;
 
   uint8_t b1 = m_cur_insn[0];
-  uint8_t b2 = m_cur_insn[1];
 
   switch (b1) {
     case 0x77: // JA/JNBE rel8
@@ -764,6 +763,7 @@ bool x86AssemblyInspectionEngine::pc_rel
       break;
   }
   if (b1 == 0x0f && opcode_size == 0) {
+    uint8_t b2 = m_cur_insn[1];
     switch (b2) {
       case 0x87: // JA/JNBE rel16/rel32
       case 0x86: // JBE/JNA rel16/rel32