[truetype] Integer overflow issues. Reported as https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6027 * src/truetype/ttinterp.c (Ins_MSIRP, Ins_MIAP, Ins_MIRP): Use SUB_LONG; avoid FT_ABS.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106
diff --git a/ChangeLog b/ChangeLog
index 71fd567..5051fa4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2018-02-06 Werner Lemberg <wl@gnu.org>
+
+ [truetype] Integer overflow issues.
+
+ Reported as
+
+ https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6027
+
+ * src/truetype/ttinterp.c (Ins_MSIRP, Ins_MIAP, Ins_MIRP): Use
+ SUB_LONG; avoid FT_ABS.
+
2018-02-04 Alexei Podtelezhnikov <apodtele@gmail.com>
[unix] Use -fvisibility=hidden.
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index 551f14a..5c8ff4f 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -5782,6 +5782,7 @@
FT_F26Dot6 distance;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
FT_F26Dot6 control_value_cutin = 0;
+ FT_F26Dot6 delta;
if ( SUBPIXEL_HINTING_INFINALITY )
@@ -5817,11 +5818,15 @@
distance = PROJECT( exc->zp1.cur + point, exc->zp0.cur + exc->GS.rp0 );
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
+ delta = SUB_LONG( distance, args[1] );
+ if ( delta < 0 )
+ delta = NEG_LONG( delta );
+
/* subpixel hinting - make MSIRP respect CVT cut-in; */
- if ( SUBPIXEL_HINTING_INFINALITY &&
- exc->ignore_x_mode &&
- exc->GS.freeVector.x != 0 &&
- FT_ABS( SUB_LONG( distance, args[1] ) ) >= control_value_cutin )
+ if ( SUBPIXEL_HINTING_INFINALITY &&
+ exc->ignore_x_mode &&
+ exc->GS.freeVector.x != 0 &&
+ delta >= control_value_cutin )
distance = args[1];
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
@@ -5978,7 +5983,14 @@
if ( ( exc->opcode & 1 ) != 0 ) /* rounding and control cut-in flag */
{
- if ( FT_ABS( distance - org_dist ) > control_value_cutin )
+ FT_F26Dot6 delta;
+
+
+ delta = SUB_LONG( distance, org_dist );
+ if ( delta < 0 )
+ delta = NEG_LONG( delta );
+
+ if ( delta > control_value_cutin )
distance = org_dist;
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
@@ -6259,6 +6271,9 @@
if ( exc->GS.gep0 == exc->GS.gep1 )
{
+ FT_F26Dot6 delta;
+
+
/* XXX: According to Greg Hitchcock, the following wording is */
/* the right one: */
/* */
@@ -6271,7 +6286,11 @@
/* `ttinst2.doc', version 1.66, is thus incorrect since */
/* it implies `>=' instead of `>'. */
- if ( FT_ABS( cvt_dist - org_dist ) > control_value_cutin )
+ delta = SUB_LONG( cvt_dist, org_dist );
+ if ( delta < 0 )
+ delta = NEG_LONG( delta );
+
+ if ( delta > control_value_cutin )
cvt_dist = org_dist;
}
@@ -6289,7 +6308,14 @@
exc->ignore_x_mode &&
exc->GS.gep0 == exc->GS.gep1 )
{
- if ( FT_ABS( cvt_dist - org_dist ) > control_value_cutin )
+ FT_F26Dot6 delta;
+
+
+ delta = SUB_LONG( cvt_dist, org_dist );
+ if ( delta < 0 )
+ delta = NEG_LONG( delta );
+
+ if ( delta > control_value_cutin )
cvt_dist = org_dist;
}
#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */