Don't use LoadLibraryEx(..., LOAD_LIBRARY_SEARCH_SYSTEM32). It hangs

Observed running hexchat under X.  For some reason the call to
	LoadLibraryEx(..., LOAD_LIBRARY_SEARCH_SYSTEM32) in dll_load
	hangs when trying to autoload MsgWaitForMultipleObjectsEx in
	select.cc after hexchat forks to run DNS calls.  Dropping the
	call and just using full paths as in 2.3.1 fixes the issue.

	* autoload.cc (dll_load): Drop call to LoadLibraryEx with
	LOAD_LIBRARY_SEARCH_SYSTEM32 flag.
	* wincap.h (wincaps::has_load_lib_search_flags): Remove.
	* wincap.cc (wincaps::has_load_lib_search_flags): Drop handling
	this flag.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This commit is contained in:
Corinna Vinschen 2016-01-27 15:43:15 +01:00
parent 78549742de
commit fcda8810a2
3 changed files with 12 additions and 30 deletions

View File

@ -332,7 +332,6 @@ union retchain
two_addr_t ll;
};
/* This function handles the problem described here:
http://www.microsoft.com/technet/security/advisory/2269637.mspx
@ -349,28 +348,20 @@ static __inline bool
dll_load (HANDLE& handle, PWCHAR name)
{
HANDLE h = NULL;
WCHAR dll_path[MAX_PATH];
/* On systems supporting LOAD_LIBRARY_SEARCH flags, try to load
explicitely from the system dir first. */
if (wincap.has_load_lib_search_flags ())
h = LoadLibraryExW (name, NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
/* If that failed, try loading with full path, which sometimes
fails for no good reason. */
wcpcpy (wcpcpy (dll_path, windows_system_directory), name);
h = LoadLibraryW (dll_path);
/* If that failed according to the second problem outlined in the
comment preceeding this function. */
if (!h && handle && wincap.use_dont_resolve_hack ()
&& GetLastError () == ERROR_INVALID_ADDRESS)
h = LoadLibraryExW (dll_path, NULL, DONT_RESOLVE_DLL_REFERENCES);
/* Last resort: Try loading just by name. */
if (!h)
{
WCHAR dll_path[MAX_PATH];
/* If that failed, try loading with full path, which sometimes
fails for no good reason. */
wcpcpy (wcpcpy (dll_path, windows_system_directory), name);
h = LoadLibraryW (dll_path);
/* If that failed according to the second problem outlined in the
comment preceeding this function. */
if (!h && handle && wincap.use_dont_resolve_hack ()
&& GetLastError () == ERROR_INVALID_ADDRESS)
h = LoadLibraryExW (dll_path, NULL, DONT_RESOLVE_DLL_REFERENCES);
/* Last resort: Try loading just by name. */
if (!h)
h = LoadLibraryW (name);
}
h = LoadLibraryW (name);
if (!h)
return false;
handle = h;

View File

@ -52,7 +52,6 @@ wincaps wincap_xpsp2 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_processor_groups:false,
has_broken_prefetchvm:false,
has_new_pebteb_region:false,
has_load_lib_search_flags:false,
};
wincaps wincap_2003 __attribute__((section (".cygwin_dll_common"), shared)) = {
@ -87,7 +86,6 @@ wincaps wincap_2003 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_processor_groups:false,
has_broken_prefetchvm:false,
has_new_pebteb_region:false,
has_load_lib_search_flags:false,
};
wincaps wincap_vista __attribute__((section (".cygwin_dll_common"), shared)) = {
@ -122,7 +120,6 @@ wincaps wincap_vista __attribute__((section (".cygwin_dll_common"), shared)) = {
has_processor_groups:false,
has_broken_prefetchvm:false,
has_new_pebteb_region:false,
has_load_lib_search_flags:true,
};
wincaps wincap_7 __attribute__((section (".cygwin_dll_common"), shared)) = {
@ -157,7 +154,6 @@ wincaps wincap_7 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_processor_groups:true,
has_broken_prefetchvm:false,
has_new_pebteb_region:false,
has_load_lib_search_flags:true,
};
wincaps wincap_8 __attribute__((section (".cygwin_dll_common"), shared)) = {
@ -192,7 +188,6 @@ wincaps wincap_8 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_processor_groups:true,
has_broken_prefetchvm:false,
has_new_pebteb_region:false,
has_load_lib_search_flags:true,
};
wincaps wincap_10 __attribute__((section (".cygwin_dll_common"), shared)) = {
@ -227,7 +222,6 @@ wincaps wincap_10 __attribute__((section (".cygwin_dll_common"), shared)) = {
has_processor_groups:true,
has_broken_prefetchvm:true,
has_new_pebteb_region:false,
has_load_lib_search_flags:true,
};
wincaps wincap_10_1511 __attribute__((section (".cygwin_dll_common"), shared)) = {
@ -262,7 +256,6 @@ wincaps wincap_10_1511 __attribute__((section (".cygwin_dll_common"), shared)) =
has_processor_groups:true,
has_broken_prefetchvm:false,
has_new_pebteb_region:true,
has_load_lib_search_flags:true,
};
wincapc wincap __attribute__((section (".cygwin_dll_common"), shared));

View File

@ -45,7 +45,6 @@ struct wincaps
unsigned has_processor_groups : 1;
unsigned has_broken_prefetchvm : 1;
unsigned has_new_pebteb_region : 1;
unsigned has_load_lib_search_flags : 1;
};
class wincapc
@ -105,7 +104,6 @@ public:
bool IMPLEMENT (has_processor_groups)
bool IMPLEMENT (has_broken_prefetchvm)
bool IMPLEMENT (has_new_pebteb_region)
bool IMPLEMENT (has_load_lib_search_flags)
#undef IMPLEMENT
};