Jacek Caban : win32u: Provide extra space in buffers used to dispatch string getter messages.
Module: wine Branch: master Commit: 10424f0dbd160bf5c76551b9098d0ba41eb4f76b URL: https://gitlab.winehq.org/wine/wine/-/commit/10424f0dbd160bf5c76551b9098d0ba...
Author: Jacek Caban jacek@codeweavers.com Date: Wed Dec 6 18:27:25 2023 +0100
win32u: Provide extra space in buffers used to dispatch string getter messages.
---
dlls/win32u/hook.c | 3 ++- dlls/win32u/message.c | 38 +++++++++++++++++++++++++------------- dlls/win32u/tests/win32u.c | 21 ++++++++++++++++++++- dlls/win32u/win32u_private.h | 2 +- 4 files changed, 48 insertions(+), 16 deletions(-)
diff --git a/dlls/win32u/hook.c b/dlls/win32u/hook.c index e9b3ae7d70d..378eda40abb 100644 --- a/dlls/win32u/hook.c +++ b/dlls/win32u/hook.c @@ -241,6 +241,7 @@ static LRESULT call_hook( struct win_hook_params *info, const WCHAR *module, siz HHOOK prev = thread_info->hook; BOOL prev_unicode = thread_info->hook_unicode; struct win_hook_params *params = info; + size_t reply_size; void *ret_ptr; ULONG ret_len;
@@ -252,7 +253,7 @@ static LRESULT call_hook( struct win_hook_params *info, const WCHAR *module, siz { CBT_CREATEWNDW *cbtc = (CBT_CREATEWNDW *)params->lparam; message_size = user_message_size( (HWND)params->wparam, WM_NCCREATE, - 0, (LPARAM)cbtc->lpcs, TRUE, FALSE ); + 0, (LPARAM)cbtc->lpcs, TRUE, FALSE, &reply_size ); lparam_size = lparam_ret_size = 0; }
diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c index 56391977eae..91f836a60bd 100644 --- a/dlls/win32u/message.c +++ b/dlls/win32u/message.c @@ -1624,11 +1624,15 @@ static size_t copy_string( void *ptr, const void *str, BOOL ansi ) * Calculate size of packed message buffer. */ size_t user_message_size( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam, - BOOL other_process, BOOL ansi ) + BOOL other_process, BOOL ansi, size_t *reply_size ) { const void *lparam_ptr = (const void *)lparam; size_t size = 0;
+ /* Windows provices space for at least 2048 bytes for string getters, which + * mitigates problems with buffer overflows. */ + static const size_t min_string_buffer_size = 2048; + switch (message) { case WM_NCCREATE: @@ -1645,8 +1649,8 @@ size_t user_message_size( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam, break; case WM_GETTEXT: case WM_ASKCBFORMATNAME: - size = wparam * char_size( ansi ); - break; + *reply_size = wparam * char_size( ansi ); + return max( *reply_size, min_string_buffer_size ); case WM_WININICHANGE: case WM_SETTEXT: case WM_DEVMODECHANGE: @@ -1730,13 +1734,17 @@ size_t user_message_size( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam, size = wparam * sizeof(UINT); break; case CB_GETLBTEXT: - size = send_message_timeout( hwnd, CB_GETLBTEXTLEN, wparam, 0, SMTO_NORMAL, 0, ansi ); - size = (size + 1) * char_size( ansi ); - break; + { + size_t len = send_message_timeout( hwnd, CB_GETLBTEXTLEN, wparam, 0, SMTO_NORMAL, 0, ansi ); + *reply_size = (len + 1) * char_size( ansi ); + return max( *reply_size, min_string_buffer_size ); + } case LB_GETTEXT: - size = send_message_timeout( hwnd, LB_GETTEXTLEN, wparam, 0, SMTO_NORMAL, 0, ansi ); - size = (size + 1) * char_size( ansi ); - break; + { + size_t len = send_message_timeout( hwnd, LB_GETTEXTLEN, wparam, 0, SMTO_NORMAL, 0, ansi ); + *reply_size = (len + 1) * char_size( ansi ); + return max( *reply_size, min_string_buffer_size ); + } case LB_GETSELITEMS: size = wparam * sizeof(UINT); break; @@ -1766,7 +1774,7 @@ size_t user_message_size( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam, break; }
- return size; + return *reply_size = size; }
/*********************************************************************** @@ -1859,6 +1867,10 @@ void pack_user_message( void *buffer, size_t size, UINT message, return; } break; + case CB_GETLBTEXT: + case LB_GETTEXT: + if (size) memset( buffer, 0, size ); + return; }
if (size) memcpy( buffer, lparam_ptr, size ); @@ -2167,7 +2179,7 @@ static LRESULT call_window_proc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar { struct win_proc_params p, *params = &p; BOOL ansi = ansi_dst && type == MSG_ASCII; - size_t packed_size = 0, offset = sizeof(*params); + size_t packed_size = 0, offset = sizeof(*params), reply_size; LRESULT result = 0; CWPSTRUCT cwp; CWPRETSTRUCT cwpret; @@ -2179,7 +2191,7 @@ static LRESULT call_window_proc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar
if (!is_current_thread_window( hwnd )) return 0;
- packed_size = user_message_size( hwnd, msg, wparam, lparam, type == MSG_OTHER_PROCESS, ansi ); + packed_size = user_message_size( hwnd, msg, wparam, lparam, type == MSG_OTHER_PROCESS, ansi, &reply_size );
/* first the WH_CALLWNDPROC hook */ cwp.lParam = lparam; @@ -2208,7 +2220,7 @@ static LRESULT call_window_proc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar result = dispatch_win_proc_params( params, offset + packed_size, &ret_ptr, &ret_len ); if (params != &p) free( params );
- copy_user_result( ret_ptr, min( ret_len, packed_size ), result, msg, wparam, lparam, ansi ); + copy_user_result( ret_ptr, min( ret_len, reply_size ), result, msg, wparam, lparam, ansi );
/* and finally the WH_CALLWNDPROCRET hook */ cwpret.lResult = result; diff --git a/dlls/win32u/tests/win32u.c b/dlls/win32u/tests/win32u.c index e118d081ead..f7fe74ed34c 100644 --- a/dlls/win32u/tests/win32u.c +++ b/dlls/win32u/tests/win32u.c @@ -1382,6 +1382,19 @@ static LPARAM callwnd_hook_lparam, callwnd_hook_lparam2, retwnd_hook_lparam, ret static LPARAM wndproc_lparam; static char lparam_buffer[521];
+static void check_zero_memory( const char *mem, size_t size ) +{ + size_t i; + for (i = 0; i < size; i++) + { + if (mem[i]) + { + ok( 0, "non-zero byte %x at offset %Iu\n", mem[i], i ); + return; + } + } +} + static void check_params( const struct lparam_hook_test *test, UINT message, WPARAM wparam, LPARAM lparam, BOOL is_ret ) { @@ -1428,8 +1441,14 @@ static void check_params( const struct lparam_hook_test *test, UINT message, } break;
+ case CB_GETLBTEXT: + case LB_GETTEXT: + check_zero_memory( (const char *)lparam, 2048 ); + break; + default: - if (test->check_size) { + if (test->check_size) + { const void *expected; if (is_ret && test->check_lparam) expected = test->check_lparam; diff --git a/dlls/win32u/win32u_private.h b/dlls/win32u/win32u_private.h index 65105c4c1a6..b08c0ceb716 100644 --- a/dlls/win32u/win32u_private.h +++ b/dlls/win32u/win32u_private.h @@ -141,7 +141,7 @@ extern BOOL send_notify_message( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar extern LRESULT send_message_timeout( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam, UINT flags, UINT timeout, BOOL ansi ); extern size_t user_message_size( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam, - BOOL other_process, BOOL ansi ); + BOOL other_process, BOOL ansi, size_t *reply_size ); extern void pack_user_message( void *buffer, size_t size, UINT message, WPARAM wparam, LPARAM lparam, BOOL ansi );
-
Alexandre Julliard