[truetype] Sanitize the broken offsets in `loca'.

* src/truetype/ttpload.c (tt_face_get_location): If `pos1', the
offset to the requested entry in `glyf' exceeds the end of the
table, return offset=0, length=0.  If `pos2', the offset to the
next entry in `glyf' exceeds the end of the table, truncate
the entry length at the end of `glyf' table.
See Savannah bug #31040.
This commit is contained in:
suzuki toshiya 2010-09-20 01:07:57 +09:00
parent 900e7e0cde
commit 643d49df09
2 changed files with 31 additions and 0 deletions

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@ -1,3 +1,14 @@
2010-09-19 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
[truetype] Sanitize the broken offsets in `loca'.
* src/truetype/ttpload.c (tt_face_get_location): If `pos1', the
offset to the requested entry in `glyf' exceeds the end of the
table, return offset=0, length=0. If `pos2', the offset to the
next entry in `glyf' exceeds the end of the table, truncate
the entry length at the end of `glyf' table.
See Savannah bug #31040.
2010-09-19 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
[sfnt] Prevent overrunning in `post' table parser.

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@ -203,6 +203,26 @@
}
}
/* Check broken location data */
if ( pos1 >= face->glyf_len )
{
FT_TRACE1(( "tt_face_get_location:"
" too large offset=0x%08lx found for gid=0x%04lx,"
" exceeding the end of glyf table (0x%08lx)\n",
pos1, gindex, face->glyf_len ));
*asize = 0;
return 0;
}
if ( pos2 >= face->glyf_len )
{
FT_TRACE1(( "tt_face_get_location:"
" too large offset=0x%08lx found for gid=0x%04lx,"
" truncate at the end of glyf table (0x%08lx)\n",
pos2, gindex + 1, face->glyf_len ));
pos2 = face->glyf_len;
}
/* The `loca' table must be ordered; it refers to the length of */
/* an entry as the difference between the current and the next */
/* position. However, there do exist (malformed) fonts which */