[psaux] Fix segfault.
Reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=10768
* src/psaux/cffdecode.c (cff_decoder_parse_charstrings)
<cff_op_callothersubr> [CFF_CONFIG_OPTION_OLD_ENGINE]: Check
argument.
diff --git a/ChangeLog b/ChangeLog
index 123cc51..c84c760 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,11 +1,23 @@
2018-10-02 Werner Lemberg <wl@gnu.org>
- [psaux] Fix numeric overflow.
+ [psaux] Fix segfault.
Reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=10768
+ * src/psaux/cffdecode.c (cff_decoder_parse_charstrings)
+ <cff_op_callothersubr> [CFF_CONFIG_OPTION_OLD_ENGINE]: Check
+ argument.
+
+2018-10-02 Werner Lemberg <wl@gnu.org>
+
+ [psaux] Fix numeric overflow.
+
+ Reported as
+
+ https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=10740
+
* src/psaux/cffdecode.c (cff_decoder_parse_charstrings) <cff_op_roll>
[CFF_CONFIG_OPTION_OLD_ENGINE]: Use NEG_INT.
diff --git a/src/psaux/cffdecode.c b/src/psaux/cffdecode.c
index b90a828..58a516f 100644
--- a/src/psaux/cffdecode.c
+++ b/src/psaux/cffdecode.c
@@ -2027,20 +2027,31 @@
break;
case cff_op_callothersubr:
- /* this is an invalid Type 2 operator; however, there */
- /* exist fonts which are incorrectly converted from probably */
- /* Type 1 to CFF, and some parsers seem to accept it */
+ {
+ FT_Fixed arg;
- FT_TRACE4(( " callothersubr (invalid op)\n" ));
- /* subsequent `pop' operands should add the arguments, */
- /* this is the implementation described for `unknown' other */
- /* subroutines in the Type1 spec. */
- /* */
- /* XXX Fix return arguments (see discussion below). */
- args -= 2 + ( args[-2] >> 16 );
- if ( args < stack )
- goto Stack_Underflow;
+ /* this is an invalid Type 2 operator; however, there */
+ /* exist fonts which are incorrectly converted from */
+ /* probably Type 1 to CFF, and some parsers seem to accept */
+ /* it */
+
+ FT_TRACE4(( " callothersubr (invalid op)\n" ));
+
+ /* subsequent `pop' operands should add the arguments, */
+ /* this is the implementation described for `unknown' */
+ /* other subroutines in the Type1 spec. */
+ /* */
+ /* XXX Fix return arguments (see discussion below). */
+
+ arg = 2 + ( args[-2] >> 16 );
+ if ( arg >= CFF_MAX_OPERANDS )
+ goto Stack_Underflow;
+
+ args -= arg;
+ if ( args < stack )
+ goto Stack_Underflow;
+ }
break;
case cff_op_pop:
