syz-cluster: fix hash comparison bugs

And improve the tests for the method.

2 files changed, 18 insertions, 9 deletions

diff --git a/syz-cluster/workflow/fuzz-step/main.go b/syz-cluster/workflow/fuzz-step/main.go
index 954c9d25c..849b8a3bf 100644
--- a/syz-cluster/workflow/fuzz-step/main.go
+++ b/syz-cluster/workflow/fuzz-step/main.go
@@ -302,16 +302,19 @@ func shouldSkipFuzzing(baseSymbols, patchedSymbols map[string]string) bool {
 		log.Logf(0, "skipped the binary equality check because some of them have 0 symbols")
 		return false
 	}
-	if len(baseSymbols) == len(patchedSymbols) {
-		for name, hash := range baseSymbols {
-			if patchedSymbols[name] != hash {
-				log.Logf(0, "binaries are different, continuing fuzzing")
-				return false
-			}
+	same := len(baseSymbols) == len(patchedSymbols)
+	for name, hash := range baseSymbols {
+		if patchedSymbols[name] != hash {
+			same = false
+			break
 		}
 	}
-	log.Logf(0, "binaries are the same, no sense to do fuzzing")
-	return true
+	if same {
+		log.Logf(0, "binaries are the same, no sense to do fuzzing")
+		return true
+	}
+	log.Logf(0, "binaries are different, continuing fuzzing")
+	return false
 }
 
 func readSymbolHashes() (base, patched map[string]string, err error) {
diff --git a/syz-cluster/workflow/fuzz-step/main_test.go b/syz-cluster/workflow/fuzz-step/main_test.go
index 49ec3b330..0336281b8 100644
--- a/syz-cluster/workflow/fuzz-step/main_test.go
+++ b/syz-cluster/workflow/fuzz-step/main_test.go
@@ -39,10 +39,16 @@ func TestShouldSkipFuzzing(t *testing.T) {
 			map[string]string{"A": "1", "B": "2"},
 		))
 	})
-	t.Run("different", func(t *testing.T) {
+	t.Run("same len, different hashes", func(t *testing.T) {
 		assert.False(t, shouldSkipFuzzing(
 			map[string]string{"A": "1", "B": "2"},
 			map[string]string{"A": "1", "B": "different"},
 		))
 	})
+	t.Run("different len, same hashes", func(t *testing.T) {
+		assert.False(t, shouldSkipFuzzing(
+			map[string]string{"A": "1", "B": "2", "C": "3"},
+			map[string]string{"A": "1", "B": "2"},
+		))
+	})
 }