Improve rule accuracy

trailofbits · Jul 19, 2023 · 1be8bb3 · 1be8bb3
1 parent 40967dd
commit 1be8bb3
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Showing 2 changed files with 35 additions and 18 deletions.
diff --git a/go/invalid-usage-of-modified-variable.go b/go/invalid-usage-of-modified-variable.go
@@ -37,8 +37,8 @@ func main() {
 	}
 
 	// ruleid: invalid-usage-of-modified-variable
-	eng11, err := getEngineerAtIndex(engineers, 5)
-	if err != nil {
+	eng11, err2 := getEngineerAtIndex(engineers, 5)
+	if err2 != nil {
 		fmt.Printf("Something")
 		fmt.Printf("Unable to obtain engineer with FName %s\n", eng11.FName)
 		fmt.Printf("Something")
@@ -60,6 +60,14 @@ func main() {
 		fmt.Printf("Something")
 	}
 
+	// ruleid: invalid-usage-of-modified-variable
+	eng14, addr1, err := getEngineerAndAddressByIndex(engineers, 5)
+	if err != nil {
+		fmt.Printf("Something")
+		fmt.Printf("Unable to obtain engineer with FName %s\n", eng14.FName)
+		fmt.Printf("Something")
+	}
+
 	// BASIC TESTS - inline if
 	// ruleid: invalid-usage-of-modified-variable
 	if eng2, err := getEngineerAtIndex(engineers, 6); err != nil {
@@ -185,19 +193,17 @@ func main() {
 		eng91 = &Engineer{0, "N/A", "N/A", 0, nil}
 	}
 
-	// TRUE POSITIVES
-
-	var eng103 *Engineer
-	// ruleid: invalid-usage-of-modified-variable
-	eng103, err = getEngineerAtIndex(engineers, 10)
+	// ok: invalid-usage-of-modified-variable
+	eng92, addr2, err := getEngineerAndAddressByIndex(engineers, 5)
 	if err != nil {
 		fmt.Printf("Something")
-		fmt.Printf("Unable to obtain engineer %d!\n", eng103.Id)
-		eng103 := &Engineer{0, "N/A", "N/A", 0, nil}
-		fmt.Printf("Unable to obtain engineer %d!\n", eng103.Id)
+		eng92, err = getEngineerAtIndex(engineers, 6)
+		fmt.Printf("Something")
 	}
 
 
+	// TRUE POSITIVES
+
 	// ruleid: invalid-usage-of-modified-variable
 	eng11, err = getEngineerAtIndex(engineers, 8)
 	if err != nil {
@@ -247,6 +253,9 @@ func main() {
 	fmt.Printf("Engineer 71: %s", fmt.Sprintf("%s %s", eng7.FName, eng71.LName))
 	fmt.Printf("Engineer 9: %s", fmt.Sprintf("%s %s", eng9.FName, eng9.LName))
 	fmt.Printf("Engineer 91: %s", fmt.Sprintf("%s %s", eng91.FName, eng91.LName))
+	fmt.Printf("Engineer 92: %s", fmt.Sprintf("%s %s", eng92.FName, eng92.LName))
+	fmt.Printf("Address 1: %v", addr1)
+	fmt.Printf("Address 2: %v", addr2)
 }
 
 func getEngineerAtIndex(slice []Engineer, idx int) (*Engineer, error) {
@@ -263,6 +272,13 @@ func getEngineerAddressByIndex(slice []Engineer, idx int) (*Address, error) {
 	return slice[idx].Address, nil
 }
 
+func getEngineerAndAddressByIndex(slice []Engineer, idx int) (*Engineer, *Address, error) {
+	if idx >= len(slice) {
+		return nil, nil, fmt.Errorf("invalid index")
+	}
+	return &slice[idx], slice[idx].Address, nil
+}
+
 func getEngineers() []Engineer {
 	return []Engineer{
 		{

diff --git a/go/invalid-usage-of-modified-variable.yaml b/go/invalid-usage-of-modified-variable.yaml
@@ -19,22 +19,23 @@ rules:
 
   patterns:
     - pattern: |
-        $X, err = ...
-        if err != nil {
+        ..., $X, ..., $ERR = ...
+        if $ERR != nil {
           ...
           <... $X ...>
         }
     - pattern-not: |
-        $X, err = ...
-        if err != nil {
+        ..., $X, ..., $ERR = ...
+        if $ERR != nil {
           ...
-          $X = ...
+          $X, ... = ...
           ...
-          <... $X ...>
         }
     - pattern-not: |
-        $X, err = ...
-        if err != nil {
+        ..., $X, ..., $ERR = ...
+        if $ERR != nil {
+          ...
           $X = ...
+          ...
         }