Fix binja backend stack string detection. Re-enable binja stack strin…

…g unit test
mandiant · Jul 24, 2023 · 8f826cb · 8f826cb
1 parent 4eabee7
commit 8f826cb
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,8 @@
 
 ### Bug Fixes
 
+- Fix binja backend stack string detection. [#1473](https://github.com/mandiant/capa/issues/1473) [@xusheng6](https://github.com/xusheng6)
+
 ### capa explorer IDA Pro plugin
 
 ### Development

diff --git a/capa/features/extractors/binja/basicblock.py b/capa/features/extractors/binja/basicblock.py
@@ -75,10 +75,11 @@ def get_stack_string_len(f: Function, il: MediumLevelILInstruction) -> int:
         return 0
 
     dest = il.params[0]
-    if dest.operation != MediumLevelILOperation.MLIL_ADDRESS_OF:
+    if dest.operation in [MediumLevelILOperation.MLIL_ADDRESS_OF, MediumLevelILOperation.MLIL_VAR]:
+        var = dest.src
+    else:
         return 0
 
-    var = dest.src
     if var.source_type != VariableSourceType.StackVariableSourceType:
         return 0
 

diff --git a/tests/test_binja_features.py b/tests/test_binja_features.py
@@ -40,9 +40,6 @@
     indirect=["sample", "scope"],
 )
 def test_binja_features(sample, scope, feature, expected):
-    if feature == capa.features.common.Characteristic("stack string"):
-        pytest.xfail("skip failing Binja stack string detection temporarily, see #1473")
-
     if isinstance(feature, capa.features.file.Export) and "." in str(feature.value):
         pytest.xfail("skip Binja unsupported forwarded export feature, see #1646")