diff options
| author | Werner Lemberg <wl@gnu.org> | 2017-03-24 09:15:10 +0100 |
|---|---|---|
| committer | Werner Lemberg <wl@gnu.org> | 2017-03-24 09:15:10 +0100 |
| commit | f958c48ee431bef8d4d466b40c9cb2d4dbcb7791 (patch) | |
| tree | 2b598e2407cf8aeaa26a1420c5732dc9971b6565 | |
| parent | 913f436d12dfe682c349eff8bf4cdd9065ff117d (diff) | |
| download | freetype2-f958c48ee431bef8d4d466b40c9cb2d4dbcb7791.tar.gz | |
[psaux] Better protect `flex' handling.
Reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=935
* src/psaux/t1decode.c (t1_decoder_parse_charstrings)
<callothersubr>: Since there is not a single flex operator but a
series of subroutine calls, malformed fonts can call arbitrary other
operators after the start of a flex, possibly adding points. For
this reason we have to check the available number of points before
inserting a point.
| -rw-r--r-- | ChangeLog | 15 | ||||
| -rw-r--r-- | src/psaux/t1decode.c | 9 |
2 files changed, 24 insertions, 0 deletions
@@ -1,5 +1,20 @@ 2017-03-23 Werner Lemberg <wl@gnu.org> + [psaux] Better protect `flex' handling. + + Reported as + + https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=935 + + * src/psaux/t1decode.c (t1_decoder_parse_charstrings) + <callothersubr>: Since there is not a single flex operator but a + series of subroutine calls, malformed fonts can call arbitrary other + operators after the start of a flex, possibly adding points. For + this reason we have to check the available number of points before + inserting a point. + +2017-03-23 Werner Lemberg <wl@gnu.org> + [sfnt] Fix check for default named instance. * src/sfnt/sfobjs.c (sfnt_init_face): A `fixed' number needs four diff --git a/src/psaux/t1decode.c b/src/psaux/t1decode.c index af7b465..7dd4513 100644 --- a/src/psaux/t1decode.c +++ b/src/psaux/t1decode.c @@ -780,10 +780,19 @@ /* point without adding any point to the outline */ idx = decoder->num_flex_vectors++; if ( idx > 0 && idx < 7 ) + { + /* in malformed fonts it is possible to have other */ + /* opcodes in the middle of a flex (which don't */ + /* increase `num_flex_vectors'); we thus have to */ + /* check whether we can add a point */ + if ( FT_SET_ERROR( t1_builder_check_points( builder, 1 ) ) ) + goto Syntax_Error; + t1_builder_add_point( builder, x, y, (FT_Byte)( idx == 3 || idx == 6 ) ); + } } break; |
