Fix 54025 (#54070)

sdmaclea · web-flow · commit b2fe66782825 · 2021-06-11T17:49:49.000-04:00
diff --git a/src/coreclr/debug/ee/controller.cpp b/src/coreclr/debug/ee/controller.cpp
@@ -4409,8 +4409,9 @@ DebuggerPatchSkip::DebuggerPatchSkip(Thread *thread,
         }
         else
         {
+            _ASSERTE(m_instrAttrib.m_cOperandSize <= SharedPatchBypassBuffer::cbBufferBypass);
             // Copy the data into our buffer.
-            memcpy(bufferBypass, patch->address + m_instrAttrib.m_cbInstr + dwOldDisp, SharedPatchBypassBuffer::cbBufferBypass);
+            memcpy(bufferBypass, patch->address + m_instrAttrib.m_cbInstr + dwOldDisp, m_instrAttrib.m_cOperandSize);
 
             if (m_instrAttrib.m_fIsWrite)
             {
diff --git a/src/coreclr/debug/ee/controller.h b/src/coreclr/debug/ee/controller.h
@@ -288,7 +288,7 @@ class SharedPatchBypassBuffer
     // "PatchBypass" must be the first field of this class for alignment to be correct.
     BYTE    PatchBypass[MAX_INSTRUCTION_LENGTH];
 #if defined(TARGET_AMD64)
-    const static int cbBufferBypass = 0x10;
+    const static int cbBufferBypass = 0x20;
     BYTE    BypassBuffer[cbBufferBypass];
 
     UINT_PTR                RipTargetFixup;

Original file line number	Diff line number	Diff line change
`@@ -4409,8 +4409,9 @@ DebuggerPatchSkip::DebuggerPatchSkip(Thread *thread,`
`4409`	`4409`	`}`
`4410`	`4410`	`else`
`4411`	`4411`	`{`
	`4412`	`+ _ASSERTE(m_instrAttrib.m_cOperandSize <= SharedPatchBypassBuffer::cbBufferBypass);`
`4412`	`4413`	`// Copy the data into our buffer.`
`4413`		`- memcpy(bufferBypass, patch->address + m_instrAttrib.m_cbInstr + dwOldDisp, SharedPatchBypassBuffer::cbBufferBypass);`
	`4414`	`+ memcpy(bufferBypass, patch->address + m_instrAttrib.m_cbInstr + dwOldDisp, m_instrAttrib.m_cOperandSize);`
`4414`	`4415`
`4415`	`4416`	`if (m_instrAttrib.m_fIsWrite)`
`4416`	`4417`	`{`