[sfnt] Prevent overrunning in `post' table parser.

* src/sfnt/ttpost.c (load_post_names): Get the length of
`post' table and pass the limit of `post' table to
load_format_20() and load_format_25().
(load_format_20): Stop the parsing when we reached at the
limit of `post' table.  If more glyph names are required,
they are filled by NULL names.  See Savannah bug #31040.
This commit is contained in:
suzuki toshiya 2010-09-20 01:03:36 +09:00
parent db053ec9a5
commit 900e7e0cde
2 changed files with 44 additions and 7 deletions

View File

@ -1,3 +1,14 @@
2010-09-19 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
[sfnt] Prevent overrunning in `post' table parser.
* src/sfnt/ttpost.c (load_post_names): Get the length of
`post' table and pass the limit of `post' table to
load_format_20() and load_format_25().
(load_format_20): Stop the parsing when we reached at the
limit of `post' table. If more glyph names are required,
they are filled by NULL names. See Savannah bug #31040.
2010-09-17 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
[truetype] Don't duplicate size->twilight structure to be freed.

View File

@ -153,7 +153,8 @@
static FT_Error
load_format_20( TT_Face face,
FT_Stream stream )
FT_Stream stream,
FT_ULong post_limit )
{
FT_Memory memory = stream->memory;
FT_Error error;
@ -230,8 +231,29 @@
FT_UInt len;
if ( FT_READ_BYTE ( len ) ||
FT_NEW_ARRAY( name_strings[n], len + 1 ) ||
FT_TRACE7(( "load_format_20: %d byte left in post table\n",
post_limit - FT_STREAM_POS() ));
if ( FT_STREAM_POS() >= post_limit )
{
FT_ERROR(( "load_format_20:"
" all entries in post table is already parsed,"
" put NULL name for gid=%d\n", n ));
len = 0;
}
else if ( FT_READ_BYTE( len ) )
goto Fail1;
if ( len > 0 && FT_STREAM_POS() + len > post_limit )
{
FT_ERROR(( "load_format_20:"
" too large string length (%d)"
" truncate at the end of post table (%d byte left)\n",
len, post_limit - FT_STREAM_POS() ));
len = FT_MAX( 0, post_limit - FT_STREAM_POS() );
}
if ( FT_NEW_ARRAY( name_strings[n], len + 1 ) ||
FT_STREAM_READ ( name_strings[n], len ) )
goto Fail1;
@ -271,7 +293,8 @@
static FT_Error
load_format_25( TT_Face face,
FT_Stream stream )
FT_Stream stream,
FT_ULong post_limit )
{
FT_Memory memory = stream->memory;
FT_Error error;
@ -338,16 +361,19 @@
FT_Stream stream;
FT_Error error;
FT_Fixed format;
FT_ULong post_len, post_limit;
/* get a stream for the face's resource */
stream = face->root.stream;
/* seek to the beginning of the PS names table */
error = face->goto_table( face, TTAG_post, stream, 0 );
error = face->goto_table( face, TTAG_post, stream, &post_len );
if ( error )
goto Exit;
post_limit = FT_STREAM_POS() + post_len;
format = face->postscript.FormatType;
/* go to beginning of subtable */
@ -356,9 +382,9 @@
/* now read postscript table */
if ( format == 0x00020000L )
error = load_format_20( face, stream );
error = load_format_20( face, stream, post_limit );
else if ( format == 0x00028000L )
error = load_format_25( face, stream );
error = load_format_25( face, stream, post_limit );
else
error = SFNT_Err_Invalid_File_Format;