Merge pull request #60 from trailofbits/hanging-gorouting-fixes

Hanging gorouting fixes
trailofbits · Jun 6, 2024 · a685fac · a685fac
2 parents c81344f + b1e14cc
commit a685fac
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Showing 2 changed files with 115 additions and 45 deletions.
diff --git a/go/hanging-goroutine.go b/go/hanging-goroutine.go
@@ -11,10 +11,9 @@ var (
 )
 
 func main() {
-	req1(1)
-	time.Sleep(time.Second * 5)
-	fmt.Println(result)
-	fmt.Println(runtime.NumGoroutine())
+	req6(1, false)
+	fmt.Println("Result: ", result)
+	fmt.Println("Goroutines (must be 1 for FPs):", runtime.NumGoroutine())
 }
 
 func req1(timeout time.Duration) string {
@@ -85,6 +84,101 @@ func req2_FP(timeout time.Duration) string {
 	}
 }
 
+func req3(timeout time.Duration) {
+	ch := make(chan string)
+	// ruleid: hanging-goroutine
+	for i := 0; i < 3; i++ {
+		go func() {
+			newData := test()
+			ch <- newData // block
+		}()
+	}
+	result = <- ch
+	fmt.Println("finished req3")
+}
+
+func req3_FP(timeout time.Duration) {
+	ch := make(chan string, 3)
+	// ok: hanging-goroutine
+	for i := 0; i < 3; i++ {
+		go func() {
+			newData := test()
+			ch <- newData // block
+		}()
+	}
+	result = <- ch
+	fmt.Println("finished req3")
+}
+
+func req4_FP(timeout time.Duration) string {
+	ch := make(chan string)
+	// ok: hanging-goroutine
+	go func() {
+		newData := test()
+		ch <- newData // block
+	}()
+	select {
+	case result = <- ch:
+		fmt.Println("case result")
+		return result
+	case <- time.After(timeout):
+		result = <- ch
+		fmt.Println("case time.Afer")
+		return ""
+	}
+}
+
+func req5_FP(timeout time.Duration) {
+	ch := make(chan string)
+	tick := time.Tick(100 * time.Millisecond)
+	quit := time.After(2 * time.Second)
+	// ok: hanging-goroutine
+	go func() {
+		newData := test()
+		ch <- newData // block
+	}()
+	for {
+		select {
+			case <-tick:
+				fmt.Print("|")
+			case <-quit:
+				result = <- ch
+				fmt.Println("\nquit")
+				return
+			default:
+				fmt.Print(".")
+				time.Sleep(50 * time.Millisecond)
+		}
+	}
+}
+
+func req6(timeout time.Duration, doclose bool) {
+	ch := make(chan string)
+	tick := time.Tick(100 * time.Millisecond)
+	quit := time.After(2 * time.Second)
+	// todoruleid: hanging-goroutine
+	go func() {
+		newData := test()
+		ch <- newData // block
+	}()
+	for {
+		select {
+			case <-tick:
+				fmt.Print("|")
+			case <-quit:
+				if doclose {
+					result = <- ch
+				}
+				fmt.Println("\nquit")
+				return
+			default:
+				fmt.Print(".")
+				time.Sleep(50 * time.Millisecond)
+		}
+	}
+}
+
+
 func test() string {
 	time.Sleep(time.Second * 2)
 	return "very important data"

diff --git a/go/hanging-goroutine.yaml b/go/hanging-goroutine.yaml
@@ -30,18 +30,6 @@ rules:
               ...
               $Y = <- $CHANNEL
               ...
-          - pattern: |
-              for ... {
-                ...
-                go func(...) {
-                  ...
-                  $CHANNEL <- $VAL
-                  ...
-                }(...)
-              }
-              ...
-              $Y := <- $CHANNEL
-              ...
           - pattern: |
               for ... {
                 ...
@@ -81,18 +69,6 @@ rules:
               case $Y = <- $CHANNEL: 
               ...
               }
-          - pattern: |
-              go func(...){
-                ...
-                $CHANNEL <- $X
-                ...
-              }(...)
-              ...
-              select {
-              case ...
-              case $Y := <- $CHANNEL: 
-              ...
-              }
           - pattern: |
               go func(...){
                 ...
@@ -117,31 +93,34 @@ rules:
               case $Y <- $CHANNEL: 
               ...
               }
-      - pattern-not: |
-          for ... {
-            ...
-            go func(...) {
-              ...
-              $CHANNEL <- $VAL
-              ...
-            }(...)
-          }
-          ...
-          $Y = <- $CHANNEL
-          ...
       - pattern-inside: |
           $CHANNEL := make(...)
           ...
       - pattern-not-inside: |
+          $CHANNEL := make(..., $T)
+          ...
+
+      # heuristics to limit FPs, we may miss some leaks because of these
+      - pattern-not: |
+          go func(...){
+            ...
+            $CHANNEL <- $X
+            ...
+          }(...)
           ...
           select {
           case ...
           case ...: 
             ...
-            ... =<- $CHANNEL
+            ... = <- $CHANNEL
             ...
           }
-      - pattern-not-inside: |
+      - pattern-not: |
+          go func(...){
+            ...
+            $CHANNEL <- $X
+            ...
+          }(...)
           ...
           select {
           case ...
@@ -150,6 +129,3 @@ rules:
             <-$CHANNEL
             ...
           }
-      - pattern-not-inside: |
-          $CHANNEL := make(..., $T)
-          ...