[CVE-2019-0590]

pleath · MikeHolman · commit 9c4772f9e8d3 · 2019-02-07T11:37:10.000-08:00
diff --git a/lib/Backend/GlobOpt.cpp b/lib/Backend/GlobOpt.cpp
@@ -2748,11 +2748,14 @@ GlobOpt::OptTagChecks(IR::Instr *instr)
                     ChangeValueType(nullptr, value, valueType.SetCanBeTaggedValue(false), true /*preserveSubClassInfo*/);
                     return false;
                 }
-                if (this->byteCodeUses)
+                if (!this->IsLoopPrePass())
                 {
-                    this->InsertByteCodeUses(instr);
+                    if (this->byteCodeUses)
+                    {
+                        this->InsertByteCodeUses(instr);
+                    }
+                    this->currentBlock->RemoveInstr(instr);
                 }
-                this->currentBlock->RemoveInstr(instr);
                 return true;
             }
 

Original file line number	Diff line number	Diff line change
`@@ -2748,11 +2748,14 @@ GlobOpt::OptTagChecks(IR::Instr *instr)`
`2748`	`2748`	`ChangeValueType(nullptr, value, valueType.SetCanBeTaggedValue(false), true /preserveSubClassInfo/);`
`2749`	`2749`	`return false;`
`2750`	`2750`	`}`
`2751`		`- if (this->byteCodeUses)`
	`2751`	`+ if (!this->IsLoopPrePass())`
`2752`	`2752`	`{`
`2753`		`- this->InsertByteCodeUses(instr);`
	`2753`	`+ if (this->byteCodeUses)`
	`2754`	`+ {`
	`2755`	`+ this->InsertByteCodeUses(instr);`
	`2756`	`+ }`
	`2757`	`+ this->currentBlock->RemoveInstr(instr);`
`2754`	`2758`	`}`
`2755`		`- this->currentBlock->RemoveInstr(instr);`
`2756`	`2759`	`return true;`
`2757`	`2760`	`}`
`2758`	`2761`