diff --git a/ChangeLog b/ChangeLog index b25a82268..62618f814 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,18 @@ +2017-09-13 suzuki toshiya + + [cache] Fix a possible overflow by signed integer comparison. + + Improve the code by 5d3ff05615dda6d1325ed612381a17a0df04c975 , + issues are found by Behdad Esfahbod and Werner Lemberg. + + * src/cache/ftcbasic.c (FTC_ImageCache_Lookup): Replace + a subtraction to check higher bit by a bit operation, + and cpp-conditionalize for appropriate systems. Add better + documentation to the comment. + (FTC_ImageCache_LookupScaler): Ditto. + (FTC_SBitCache_Lookup): Ditto. + (FTC_SBitCache_LookupScaler): Ditto. + 2017-09-13 Werner Lemberg [autofit] Really fix #41334 (#52000). diff --git a/src/cache/ftcbasic.c b/src/cache/ftcbasic.c index 289bd5c43..59221f2fa 100644 --- a/src/cache/ftcbasic.c +++ b/src/cache/ftcbasic.c @@ -304,10 +304,19 @@ if ( anode ) *anode = NULL; - if ( (FT_ULong)( type->flags - FT_INT_MIN ) > FT_UINT_MAX ) +/* + * internal FTC_BasicAttr->load_flags is typed FT_UInt, + * but public FT_ImageType->flags is typed FT_Int32 + * + * On 16bit systems, higher bits of type->flags + * could not be handled. + */ +#if 0xFFFFFFFFUL > FT_UINT_MAX + if ( (type->flags & (FT_ULong)FT_UINT_MAX) ) FT_TRACE1(( "FTC_ImageCache_Lookup:" " higher bits in load_flags 0x%x are dropped\n", (FT_ULong)type->flags & ~((FT_ULong)FT_UINT_MAX) )); +#endif query.attrs.scaler.face_id = type->face_id; query.attrs.scaler.width = type->width; @@ -377,11 +386,19 @@ if ( anode ) *anode = NULL; - /* `FT_Load_Glyph' and `FT_Load_Char' take FT_UInt flags */ +/* + * internal FTC_BasicAttr->load_flags is typed FT_UInt, + * but public FT_Face->face_flags is typed FT_Long. + * + * On long > int systems, higher bits of load_flags + * could not be handled. + */ +#if FT_ULONG_MAX > FT_UINT_MAX if ( load_flags > FT_UINT_MAX ) FT_TRACE1(( "FTC_ImageCache_LookupScaler:" " higher bits in load_flags 0x%x are dropped\n", load_flags & ~((FT_ULong)FT_UINT_MAX) )); +#endif query.attrs.scaler = scaler[0]; query.attrs.load_flags = (FT_UInt)load_flags; @@ -487,10 +504,19 @@ *ansbit = NULL; - if ( (FT_ULong)( type->flags - FT_INT_MIN ) > FT_UINT_MAX ) +/* + * internal FTC_BasicAttr->load_flags is typed FT_UInt, + * but public FT_ImageType->flags is typed FT_Int32 + * + * On 16bit systems, higher bits of type->flags + * could not be handled. + */ +#if 0xFFFFFFFFUL > FT_UINT_MAX + if ( (type->flags & (FT_ULong)FT_UINT_MAX) ) FT_TRACE1(( "FTC_ImageCache_Lookup:" " higher bits in load_flags 0x%x are dropped\n", (FT_ULong)type->flags & ~((FT_ULong)FT_UINT_MAX) )); +#endif query.attrs.scaler.face_id = type->face_id; query.attrs.scaler.width = type->width; @@ -562,11 +588,19 @@ *ansbit = NULL; - /* `FT_Load_Glyph' and `FT_Load_Char' take FT_UInt flags */ +/* + * internal FTC_BasicAttr->load_flags is typed FT_UInt, + * but public FT_Face->face_flags is typed FT_Long. + * + * On long > int systems, higher bits of load_flags + * could not be handled. + */ +#if FT_ULONG_MAX > FT_UINT_MAX if ( load_flags > FT_UINT_MAX ) FT_TRACE1(( "FTC_ImageCache_LookupScaler:" " higher bits in load_flags 0x%x are dropped\n", load_flags & ~((FT_ULong)FT_UINT_MAX) )); +#endif query.attrs.scaler = scaler[0]; query.attrs.load_flags = (FT_UInt)load_flags;