Commit 40f28e56 authored by Kyle Huey's avatar Kyle Huey
Browse files

Bug 730051: Don't use SearchPathW to look for the DLL unless we're actually... 

Bug 730051: Don't use SearchPathW to look for the DLL unless we're actually doing a load. r=bsmedberg
parent b3cc90d0

toolkit/xre/nsWindowsDllBlocklist.cpp

+34 −16
Original line number Diff line number Diff line
@@ -278,18 +278,9 @@ private: 
CRITICAL_SECTION ReentrancySentinel::sLock;

std::map<DWORD, const char*>* ReentrancySentinel::sThreadMap;



static NTSTATUS NTAPI

patched_LdrLoadDll (PWCHAR filePath, PULONG flags, PUNICODE_STRING moduleFileName, PHANDLE handle)

static

wchar_t* getFullPath (PWCHAR filePath, wchar_t* fname)

{

  // We have UCS2 (UTF16?), we want ASCII, but we also just want the filename portion

#define DLLNAME_MAX 128

  char dllName[DLLNAME_MAX+1];

  wchar_t *dll_part;

  DllBlockInfo *info;



  int len = moduleFileName->Length / 2;

  wchar_t *fname = moduleFileName->Buffer;



  // In Windows 8, the first parameter seems to be used for more than just the

  // path name.  For example, its numerical value can be 1.  Passing a non-valid

  // pointer to SearchPathW will cause a crash, so we need to check to see if we
@@ -299,19 +290,32 @@ patched_LdrLoadDll (PWCHAR filePath, PULONG flags, PUNICODE_STRING moduleFileNam 
  // figure out the length of the string that we need

  DWORD pathlen = SearchPathW(sanitizedFilePath, fname, L".dll", 0, NULL, NULL);

  if (pathlen == 0) {

    // uh, we couldn't find the DLL at all, so...

    printf_stderr("LdrLoadDll: Blocking load of '%s' (SearchPathW didn't find it?)\n", dllName);

    return STATUS_DLL_NOT_FOUND;

    return nsnull;

  }



  nsAutoArrayPtr<wchar_t> full_fname(new wchar_t[pathlen+1]);

  wchar_t* full_fname = new wchar_t[pathlen+1];

  if (!full_fname) {

    // couldn't allocate memory?

    return STATUS_DLL_NOT_FOUND;

    return nsnull;

  }



  // now actually grab it

  SearchPathW(sanitizedFilePath, fname, L".dll", pathlen+1, full_fname, NULL);

  return full_fname;

}



static NTSTATUS NTAPI

patched_LdrLoadDll (PWCHAR filePath, PULONG flags, PUNICODE_STRING moduleFileName, PHANDLE handle)

{

  // We have UCS2 (UTF16?), we want ASCII, but we also just want the filename portion

#define DLLNAME_MAX 128

  char dllName[DLLNAME_MAX+1];

  wchar_t *dll_part;

  DllBlockInfo *info;



  int len = moduleFileName->Length / 2;

  wchar_t *fname = moduleFileName->Buffer;

  nsAutoArrayPtr<wchar_t> full_fname;



  // The filename isn't guaranteed to be null terminated, but in practice

  // it always will be; ensure that this is so, and bail if not.
@@ -393,6 +397,13 @@ patched_LdrLoadDll (PWCHAR filePath, PULONG flags, PUNICODE_STRING moduleFileNam 
        goto continue_loading;

      }



      full_fname = getFullPath(filePath, fname);

      if (!full_fname) {

        // uh, we couldn't find the DLL at all, so...

        printf_stderr("LdrLoadDll: Blocking load of '%s' (SearchPathW didn't find it?)\n", dllName);

        return STATUS_DLL_NOT_FOUND;

      }



      DWORD zero;

      DWORD infoSize = GetFileVersionInfoSizeW(full_fname, &zero);
@@ -433,6 +444,13 @@ continue_loading: 


  if (gInXPCOMLoadOnMainThread && NS_IsMainThread()) {

    // Check to ensure that the DLL has ASLR.

    full_fname = getFullPath(filePath, fname);

    if (!full_fname) {

      // uh, we couldn't find the DLL at all, so...

      printf_stderr("LdrLoadDll: Blocking load of '%s' (SearchPathW didn't find it?)\n", dllName);

      return STATUS_DLL_NOT_FOUND;

    }



    if (!CheckASLR(full_fname)) {

      printf_stderr("LdrLoadDll: Blocking load of '%s'.  XPCOM components must support ASLR.\n", dllName);

      return STATUS_DLL_NOT_FOUND;