[PATCH v2 0/2] MR3755: win32u: Correct the packed size of WM_GETDLGCODE when lparam is NULL.

[Tim Clem (＠tclem)]

If lparam is null, the current code crashes when it hits the memcpy in pack_user_message.

--
  v2: win32u: Correct the packed size of WM_GETDLGCODE when lparam is NULL.
      win32u: Add a test for cross-process WM_GETDLGCODE with a NULL lparam.

https://gitlab.winehq.org/wine/wine/-/merge_requests/3755

[PATCH v2 1/2] win32u: Add a test for cross-process WM_GETDLGCODE with a NULL lparam.

[Tim Clem]

From: Tim Clem

Co-authored-by: Jacek Caban 
---
 dlls/win32u/tests/win32u.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/dlls/win32u/tests/win32u.c b/dlls/win32u/tests/win32u.c
index 25358c5d0d8..efc7249eca7 100644
--- a/dlls/win32u/tests/win32u.c
+++ b/dlls/win32u/tests/win32u.c
@@ -964,6 +964,9 @@ static LRESULT WINAPI test_ipc_message_proc( HWND hwnd, UINT msg, WPARAM wparam,
             ok( !wcscmp( mdi->szTitle, L"TestTitle" ), "szTitle = %s\n", wine_dbgstr_w( mdi->szTitle ));
             return 0xdeadbeef;
         }
+
+    case WM_GETDLGCODE:
+        return !lparam;
     }

return DefWindowProcW( hwnd, msg, wparam, lparam );
@@ -1059,6 +1062,10 @@ static void test_inter_process_child( HWND hwnd )
     res = NtUserMessageCall( hwnd, WM_GETTEXTLENGTH, 0, 0, NULL, NtUserSendMessage, TRUE );
     ok( res == 4, "res = %d\n", res );

+    res = NtUserMessageCall( hwnd, WM_GETDLGCODE, 0, 0, NULL, NtUserSendMessage, TRUE );
+    todo_wine
+    ok( res == 1, "res = %d\n", res );
+
     mdi.szClass = "TestClass";
     mdi.szTitle = "TestTitle";
     mdi.hOwner = 0;

[PATCH v2 2/2] win32u: Correct the packed size of WM_GETDLGCODE when lparam is NULL.

[Tim Clem]

From: Tim Clem

---
 dlls/win32u/message.c      | 2 +-
 dlls/win32u/tests/win32u.c | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c
index d15f9af3f9f..d2909339983 100644
--- a/dlls/win32u/message.c
+++ b/dlls/win32u/message.c
@@ -1691,7 +1691,7 @@ size_t user_message_size( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam,
         size = sizeof(STYLESTRUCT);
         break;
     case WM_GETDLGCODE:
-        size = sizeof(MSG);
+        if (lparam) size = sizeof(MSG);
         break;
     case SBM_SETSCROLLINFO:
     case SBM_GETSCROLLINFO:
diff --git a/dlls/win32u/tests/win32u.c b/dlls/win32u/tests/win32u.c
index efc7249eca7..e118d081ead 100644
--- a/dlls/win32u/tests/win32u.c
+++ b/dlls/win32u/tests/win32u.c
@@ -1063,7 +1063,6 @@ static void test_inter_process_child( HWND hwnd )
     ok( res == 4, "res = %d\n", res );

res = NtUserMessageCall( hwnd, WM_GETDLGCODE, 0, 0, NULL, NtUserSendMessage, TRUE );
-    todo_wine
     ok( res == 1, "res = %d\n", res );

mdi.szClass = "TestClass";

[Tim Clem (＠tclem)]

On Fri Sep  8 16:15:08 2023 +0000, Jacek Caban wrote:
> The fix looks good, but it would be nice to have a test. Please include
> something like the [attached test](/uploads/4ff2f549a3d6edd1d7076f2968c584e2/patch.diff).

Ah, thanks! I saw an existing test with a null lparam but didn't think to consider that it needed to be IPC to hit this code path. Added your test in v2.

[PATCH v2 0/2] MR3755: win32u: Correct the packed size of WM_GETDLGCODE when lparam is NULL. - approved

[Jacek Caban (＠jacek)]

This merge request was approved by Jacek Caban.