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kernel32: Attempt to buffer the full directory in FindFirstFile to avoid races.

This commit is contained in:
Alexandre Julliard 2013-02-18 14:50:57 +01:00
parent 38e8f6d83f
commit 7ce90cc719
1 changed files with 52 additions and 11 deletions
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51
dlls/kernel32/file.c
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@ -61,11 +61,14 @@ typedef struct
BOOL is_root; /* is directory the root of the drive? */
UINT data_pos; /* current position in dir data */
UINT data_len; /* length of dir data */
BYTE data[8192]; /* directory data */
UINT data_size; /* size of data buffer, or 0 when everything has been read */
BYTE *data; /* directory data */
} FIND_FIRST_INFO;
#define FIND_FIRST_MAGIC 0xc0ffee11
static const UINT max_entry_size = offsetof( FILE_BOTH_DIRECTORY_INFORMATION, FileName[256] );
static BOOL oem_file_apis;
static const WCHAR wildcardsW[] = { '*','?',0 };
@ -1930,6 +1933,8 @@ HANDLE WINAPI FindFirstFileExW( LPCWSTR filename, FINDEX_INFO_LEVELS level,
info->magic = FIND_FIRST_MAGIC;
info->data_pos = 0;
info->data_len = 0;
info->data_size = 0;
info->data = NULL;
info->search_op = search_op;
if (device)
@ -1945,8 +1950,20 @@ HANDLE WINAPI FindFirstFileExW( LPCWSTR filename, FINDEX_INFO_LEVELS level,
else
{
IO_STATUS_BLOCK io;
BOOL has_wildcard = strpbrkW( info->mask.Buffer, wildcardsW ) != NULL;
NtQueryDirectoryFile( info->handle, 0, NULL, NULL, &io, info->data, sizeof(info->data),
info->data_size = has_wildcard ? 8192 : max_entry_size;
while (info->data_size)
{
if (!(info->data = HeapAlloc( GetProcessHeap(), 0, info->data_size )))
{
FindClose( info );
SetLastError( ERROR_NOT_ENOUGH_MEMORY );
return INVALID_HANDLE_VALUE;
}
NtQueryDirectoryFile( info->handle, 0, NULL, NULL, &io, info->data, info->data_size,
FileBothDirectoryInformation, FALSE, &info->mask, TRUE );
if (io.u.Status)
{
@ -1954,7 +1971,23 @@ HANDLE WINAPI FindFirstFileExW( LPCWSTR filename, FINDEX_INFO_LEVELS level,
SetLastError( RtlNtStatusToDosError( io.u.Status ) );
return INVALID_HANDLE_VALUE;
}
if (io.Information < info->data_size - max_entry_size)
{
info->data_size = 0; /* we read everything */
}
else if (info->data_size < 1024 * 1024)
{
HeapFree( GetProcessHeap(), 0, info->data );
info->data_size *= 2;
}
else break;
}
info->data_len = io.Information;
if (!info->data_size && has_wildcard) /* release unused buffer space */
HeapReAlloc( GetProcessHeap(), HEAP_REALLOC_IN_PLACE_ONLY, info->data, info->data_len );
if (!FindNextFileW( info, data ))
{
TRACE( "%s not found\n", debugstr_w(filename) );
@ -1962,11 +1995,12 @@ HANDLE WINAPI FindFirstFileExW( LPCWSTR filename, FINDEX_INFO_LEVELS level,
SetLastError( ERROR_FILE_NOT_FOUND );
return INVALID_HANDLE_VALUE;
}
if (!strpbrkW( info->mask.Buffer, wildcardsW ))
if (!has_wildcard) /* we can't find two files with the same name */
{
/* we can't find two files with the same name */
CloseHandle( info->handle );
HeapFree( GetProcessHeap(), 0, info->data );
info->handle = 0;
info->data = NULL;
}
}
return info;
@ -2010,15 +2044,21 @@ BOOL WINAPI FindNextFileW( HANDLE handle, WIN32_FIND_DATAW *data )
{
IO_STATUS_BLOCK io;
NtQueryDirectoryFile( info->handle, 0, NULL, NULL, &io, info->data, sizeof(info->data),
if (info->data_size)
NtQueryDirectoryFile( info->handle, 0, NULL, NULL, &io, info->data, info->data_size,
FileBothDirectoryInformation, FALSE, &info->mask, FALSE );
else
io.u.Status = STATUS_NO_MORE_FILES;
if (io.u.Status)
{
SetLastError( RtlNtStatusToDosError( io.u.Status ) );
if (io.u.Status == STATUS_NO_MORE_FILES)
{
CloseHandle( info->handle );
HeapFree( GetProcessHeap(), 0, info->data );
info->handle = 0;
info->data = NULL;
}
break;
}
@ -2101,6 +2141,7 @@ BOOL WINAPI FindClose( HANDLE handle )
RtlFreeUnicodeString( &info->path );
info->data_pos = 0;
info->data_len = 0;
HeapFree( GetProcessHeap(), 0, info->data );
RtlLeaveCriticalSection( &info->cs );
info->cs.DebugInfo->Spare[0] = 0;
RtlDeleteCriticalSection( &info->cs );