gh-111178: fix UBSan failures in Modules/_lzmamodule.c (GH-129783)

picnixz · web-flow · commit 185ac5adafb7 · 2025-02-18T14:48:21.000+01:00
fix UBSan failures for LZMA objects

suppress unused return values
diff --git a/Modules/_lzmamodule.c b/Modules/_lzmamodule.c
@@ -126,6 +126,9 @@ typedef struct {
     PyThread_type_lock lock;
 } Decompressor;
 
+#define Compressor_CAST(op)     ((Compressor *)(op))
+#define Decompressor_CAST(op)   ((Decompressor *)(op))
+
 /* Helper functions. */
 
 static int
@@ -857,14 +860,15 @@ Compressor_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 }
 
 static void
-Compressor_dealloc(Compressor *self)
+Compressor_dealloc(PyObject *op)
 {
+    Compressor *self = Compressor_CAST(op);
     lzma_end(&self->lzs);
     if (self->lock != NULL) {
         PyThread_free_lock(self->lock);
     }
     PyTypeObject *tp = Py_TYPE(self);
-    tp->tp_free((PyObject *)self);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -875,7 +879,7 @@ static PyMethodDef Compressor_methods[] = {
 };
 
 static int
-Compressor_traverse(Compressor *self, visitproc visit, void *arg)
+Compressor_traverse(PyObject *self, visitproc visit, void *arg)
 {
     Py_VISIT(Py_TYPE(self));
     return 0;
@@ -1304,8 +1308,9 @@ _lzma_LZMADecompressor_impl(PyTypeObject *type, int format,
 }
 
 static void
-Decompressor_dealloc(Decompressor *self)
+Decompressor_dealloc(PyObject *op)
 {
+    Decompressor *self = Decompressor_CAST(op);
     if(self->input_buffer != NULL)
         PyMem_Free(self->input_buffer);
 
@@ -1315,12 +1320,12 @@ Decompressor_dealloc(Decompressor *self)
         PyThread_free_lock(self->lock);
     }
     PyTypeObject *tp = Py_TYPE(self);
-    tp->tp_free((PyObject *)self);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
 static int
-Decompressor_traverse(Decompressor *self, visitproc visit, void *arg)
+Decompressor_traverse(PyObject *self, visitproc visit, void *arg)
 {
     Py_VISIT(Py_TYPE(self));
     return 0;
@@ -1633,7 +1638,7 @@ lzma_clear(PyObject *module)
 static void
 lzma_free(void *module)
 {
-    lzma_clear((PyObject *)module);
+    (void)lzma_clear((PyObject *)module);
 }
 
 static PyModuleDef _lzmamodule = {

Original file line number	Diff line number	Diff line change
`@@ -126,6 +126,9 @@ typedef struct {`
`126`	`126`	`PyThread_type_lock lock;`
`127`	`127`	`} Decompressor;`
`128`	`128`
	`129`	`+#define Compressor_CAST(op) ((Compressor *)(op))`
	`130`	`+#define Decompressor_CAST(op) ((Decompressor *)(op))`
	`131`	`+`
`129`	`132`	`/* Helper functions. */`
`130`	`133`
`131`	`134`	`static int`
`@@ -857,14 +860,15 @@ Compressor_new(PyTypeObject type, PyObject args, PyObject *kwargs)`
`857`	`860`	`}`
`858`	`861`
`859`	`862`	`static void`
`860`		`-Compressor_dealloc(Compressor *self)`
	`863`	`+Compressor_dealloc(PyObject *op)`
`861`	`864`	`{`
	`865`	`+ Compressor *self = Compressor_CAST(op);`
`862`	`866`	`lzma_end(&self->lzs);`
`863`	`867`	`if (self->lock != NULL) {`
`864`	`868`	`PyThread_free_lock(self->lock);`
`865`	`869`	`}`
`866`	`870`	`PyTypeObject *tp = Py_TYPE(self);`
`867`		`- tp->tp_free((PyObject *)self);`
	`871`	`+ tp->tp_free(self);`
`868`	`872`	`Py_DECREF(tp);`
`869`	`873`	`}`
`870`	`874`
`@@ -875,7 +879,7 @@ static PyMethodDef Compressor_methods[] = {`
`875`	`879`	`};`
`876`	`880`
`877`	`881`	`static int`
`878`		`-Compressor_traverse(Compressor self, visitproc visit, void arg)`
	`882`	`+Compressor_traverse(PyObject self, visitproc visit, void arg)`
`879`	`883`	`{`
`880`	`884`	`Py_VISIT(Py_TYPE(self));`
`881`	`885`	`return 0;`
`@@ -1304,8 +1308,9 @@ _lzma_LZMADecompressor_impl(PyTypeObject *type, int format,`
`1304`	`1308`	`}`
`1305`	`1309`
`1306`	`1310`	`static void`
`1307`		`-Decompressor_dealloc(Decompressor *self)`
	`1311`	`+Decompressor_dealloc(PyObject *op)`
`1308`	`1312`	`{`
	`1313`	`+ Decompressor *self = Decompressor_CAST(op);`
`1309`	`1314`	`if(self->input_buffer != NULL)`
`1310`	`1315`	`PyMem_Free(self->input_buffer);`
`1311`	`1316`
`@@ -1315,12 +1320,12 @@ Decompressor_dealloc(Decompressor *self)`
`1315`	`1320`	`PyThread_free_lock(self->lock);`
`1316`	`1321`	`}`
`1317`	`1322`	`PyTypeObject *tp = Py_TYPE(self);`
`1318`		`- tp->tp_free((PyObject *)self);`
	`1323`	`+ tp->tp_free(self);`
`1319`	`1324`	`Py_DECREF(tp);`
`1320`	`1325`	`}`
`1321`	`1326`
`1322`	`1327`	`static int`
`1323`		`-Decompressor_traverse(Decompressor self, visitproc visit, void arg)`
	`1328`	`+Decompressor_traverse(PyObject self, visitproc visit, void arg)`
`1324`	`1329`	`{`
`1325`	`1330`	`Py_VISIT(Py_TYPE(self));`
`1326`	`1331`	`return 0;`
`@@ -1633,7 +1638,7 @@ lzma_clear(PyObject *module)`
`1633`	`1638`	`static void`
`1634`	`1639`	`lzma_free(void *module)`
`1635`	`1640`	`{`
`1636`		`- lzma_clear((PyObject *)module);`
	`1641`	`+ (void)lzma_clear((PyObject *)module);`
`1637`	`1642`	`}`
`1638`	`1643`
`1639`	`1644`	`static PyModuleDef _lzmamodule = {`