From: "Roman Pišl" Subject: [PATCH] user32: Avoid buffer overflow on long texts in winproc. Message-Id: <20200206173357.32190-1-rpisl@seznam.cz> Date: Thu, 6 Feb 2020 18:33:57 +0100 Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=48559 Signed-off-by: Roman Pišl --- dlls/user32/winproc.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/dlls/user32/winproc.c b/dlls/user32/winproc.c index 6de650cd1e..14555f5a71 100644 --- a/dlls/user32/winproc.c +++ b/dlls/user32/winproc.c @@ -517,16 +517,21 @@ LRESULT WINPROC_CallProcAtoW( winproc_callback_t callback, HWND hwnd, UINT msg, case CB_GETLBTEXT: if (lParam && WINPROC_TestLBForStr( hwnd, msg )) { - WCHAR buffer[512]; /* FIXME: fixed sized buffer */ + WCHAR *ptr, buffer[512]; + UINT msgGetTextLen = (msg == CB_GETLBTEXT) ? CB_GETLBTEXTLEN : LB_GETTEXTLEN; + LRESULT len = 0; - ret = callback( hwnd, msg, wParam, (LPARAM)buffer, result, arg ); + callback( hwnd, msgGetTextLen, wParam, 0, &len, arg ); + if (!(ptr = get_buffer( buffer, sizeof(buffer), (len + 1) * sizeof(WCHAR) ))) break; + ret = callback( hwnd, msg, wParam, (LPARAM)ptr, result, arg ); if (*result >= 0) { DWORD len; RtlUnicodeToMultiByteN( (LPSTR)lParam, ~0u, &len, - buffer, (strlenW(buffer) + 1) * sizeof(WCHAR) ); + ptr, (strlenW(ptr) + 1) * sizeof(WCHAR) ); *result = len - 1; } + free_buffer( buffer, ptr ); } else ret = callback( hwnd, msg, wParam, lParam, result, arg ); break; @@ -777,15 +782,20 @@ static LRESULT WINPROC_CallProcWtoA( winproc_callback_t callback, HWND hwnd, UIN case CB_GETLBTEXT: if (lParam && WINPROC_TestLBForStr( hwnd, msg )) { - char buffer[512]; /* FIXME: fixed sized buffer */ + char *ptr, buffer[512]; + UINT msgGetTextLen = (msg == CB_GETLBTEXT) ? CB_GETLBTEXTLEN : LB_GETTEXTLEN; + LRESULT len = 0; + callback( hwnd, msgGetTextLen, wParam, 0, &len, arg ); + if (!(ptr = get_buffer( buffer, sizeof(buffer), len + 1 ))) break; - ret = callback( hwnd, msg, wParam, (LPARAM)buffer, result, arg ); + ret = callback( hwnd, msg, wParam, (LPARAM)ptr, result, arg ); if (*result >= 0) { DWORD len; - RtlMultiByteToUnicodeN( (LPWSTR)lParam, ~0u, &len, buffer, strlen(buffer) + 1 ); + RtlMultiByteToUnicodeN( (LPWSTR)lParam, ~0u, &len, ptr, strlen(ptr) + 1 ); *result = len / sizeof(WCHAR) - 1; } + free_buffer( buffer, ptr ); } else ret = callback( hwnd, msg, wParam, lParam, result, arg ); break; -- 2.20.1