[PATCH v16 0/3] MR9632: sxs: avoid uninitialised len_name length

[Hans Chen (＠hans.chen)]

The `redirect_data->clrdata_len` [is unset in /dlls/ntdll/actctx.c#L4411-4412](https://gitlab.winehq.org/wine/wine/-/blob/master/dlls/ntdll/actctx.c?ref_ty...) when using registration-free COM in C# NET code.

Program.cs

```C#
//...


Guid guid = Guid.Parse("COM clsid");
Type type = Type.GetTypeFromCLSID(guid, true);
var instance = Activator.CreateInstance(type));
//...

```

App.manifest

```xml
<assembly>
  <file name="ExampleCOM.dll">
    <comClass description="ExampleCOM" progid="ExampleCOM" clsid="{COM clsid}" threadingModel="Free"/>
  </file>
</assembly>
```

The above C# code gets this error on its second line.

```Shell
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
```

This is because `len_name` is uninitialized when calling `memcpy(ret_strings, ptr_name, len_name);` in `SxsLookupClrGuid`, which is fixed in this MR.

--
  v16: force to call prepare_and_run_test
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/9632

[PATCH v16 1/3] sxs: avoid uninitialised len_name

[Hans Chen]

From: Hans Chen <[e-mail]>

---
 dlls/sxs/sxs.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/dlls/sxs/sxs.c b/dlls/sxs/sxs.c
index 150a49a322f..2b89bf369f0 100644
--- a/dlls/sxs/sxs.c
+++ b/dlls/sxs/sxs.c
@@ -97,7 +97,7 @@ BOOL WINAPI SxsLookupClrGuid(DWORD flags, GUID *clsid, HANDLE actctx, void *buff
     ACTCTX_SECTION_KEYED_DATA guid_info = { sizeof(ACTCTX_SECTION_KEYED_DATA) };
     ACTIVATION_CONTEXT_ASSEMBLY_DETAILED_INFORMATION *assembly_info = NULL;
     SIZE_T bytes_assembly_info;
-    unsigned int len_version = 0, len_name, len_identity;
+    unsigned int len_version = 0, len_name = 0, len_identity = 0;
     const void *ptr_name, *ptr_version, *ptr_identity;
     SXS_GUID_INFORMATION_CLR *ret = buffer;
     BOOL retval = FALSE;
@@ -160,12 +160,15 @@ BOOL WINAPI SxsLookupClrGuid(DWORD flags, GUID *clsid, HANDLE actctx, void *buff
         const struct comclassredirect_data *redirect_data = guid_info.lpData;
         const struct clrclass_data *class_data;
 
-        class_data = (void *)((char *)redirect_data + redirect_data->clrdata_offset);
-        ptr_name = (char *)class_data + class_data->name_offset;
-        ptr_version = (char *)class_data + class_data->version_offset;
-        len_name = class_data->name_len + sizeof(WCHAR);
-        if (class_data->version_len)
-            len_version = class_data->version_len + sizeof(WCHAR);
+        if(redirect_data->clrdata_len)
+        {
+            class_data = (void *)((char *)redirect_data + redirect_data->clrdata_offset);
+            ptr_name = (char *)class_data + class_data->name_offset;
+            ptr_version = (char *)class_data + class_data->version_offset;
+            len_name = class_data->name_len + sizeof(WCHAR);
+            if (class_data->version_len)
+                len_version = class_data->version_len + sizeof(WCHAR);
+        }
     }
     else
     {
@@ -199,10 +202,15 @@ BOOL WINAPI SxsLookupClrGuid(DWORD flags, GUID *clsid, HANDLE actctx, void *buff
     ret->pcwszAssemblyIdentity = (WCHAR *)ret_strings;
     ret_strings += len_identity;
 
-    memcpy(ret_strings, ptr_name, len_name);
-    ret->pcwszTypeName = (WCHAR *)ret_strings;
-    ret_strings += len_name;
-
+    if(len_name > 0)
+    {
+        memcpy(ret_strings, ptr_name, len_name);
+        ret->pcwszTypeName = (WCHAR *)ret_strings;
+        ret_strings += len_name;
+    }
+    else
+        ret->pcwszTypeName = NULL;
+        
     if (len_version > 0)
     {
         memcpy(ret_strings, ptr_version, len_version);
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/9632

[PATCH v16 2/3] add a blank line to trigger tests running

[Hans Chen]

From: Hans Chen <[e-mail]>

---
 dlls/sxs/tests/comtest_exe.manifest | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dlls/sxs/tests/comtest_exe.manifest b/dlls/sxs/tests/comtest_exe.manifest
index bc9ce4c0457..fda42a4597e 100644
--- a/dlls/sxs/tests/comtest_exe.manifest
+++ b/dlls/sxs/tests/comtest_exe.manifest
@@ -8,4 +8,5 @@
                 type="win32"/>
         </dependentAssembly>
     </dependency>
+
 </assembly>
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/9632

[PATCH v16 3/3] force to call prepare_and_run_test

[Hans Chen]

From: Hans Chen <[e-mail]>

---
 dlls/sxs/tests/sxs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/dlls/sxs/tests/sxs.c b/dlls/sxs/tests/sxs.c
index 9bcb85c69aa..5cce589cd1d 100644
--- a/dlls/sxs/tests/sxs.c
+++ b/dlls/sxs/tests/sxs.c
@@ -262,11 +262,11 @@ START_TEST(sxs)
 {
     char **argv;
     int argc = winetest_get_mainargs(&argv);
-    if (argc > 2)
-    {
+    // if (argc > 2)
+    // {
         prepare_and_run_test();
         return;
-    }
+    // }
 
-    test_SxsLookupClrGuid();
+    // test_SxsLookupClrGuid();
 }
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/9632