accounts/abi: fix panic in MethodById lookup (ethereum#17798)

gzliudan · Jan 3, 2025 · dea4223 · dea4223
1 parent 335467b
commit dea4223
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go
@@ -140,6 +140,9 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 // MethodById looks up a method by the 4-byte id
 // returns nil if none found
 func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
+	if len(sigdata) < 4 {
+		return nil, fmt.Errorf("data too short (% bytes) for abi method lookup", len(sigdata))
+	}
 	for _, method := range abi.Methods {
 		if bytes.Equal(method.Id(), sigdata[:4]) {
 			return &method, nil

diff --git a/accounts/abi/abi_test.go b/accounts/abi/abi_test.go
@@ -716,7 +716,16 @@ func TestABI_MethodById(t *testing.T) {
 			t.Errorf("Method %v (id %v) not 'findable' by id in ABI", name, hexutil.Encode(m.Id()))
 		}
 	}
-
+	// Also test empty
+	if _, err := abi.MethodById([]byte{0x00}); err == nil {
+		t.Errorf("Expected error, too short to decode data")
+	}
+	if _, err := abi.MethodById([]byte{}); err == nil {
+		t.Errorf("Expected error, too short to decode data")
+	}
+	if _, err := abi.MethodById(nil); err == nil {
+		t.Errorf("Expected error, nil is short to decode data")
+	}
 }
 
 func TestUnpackRevert(t *testing.T) {