From 53dfdcd8198d2b3201a23c4bad9190519ba918db Mon Sep 17 00:00:00 2001 From: Werner Lemberg Date: Thu, 17 Mar 2022 19:24:16 +0100 Subject: [PATCH] [sfnt] Avoid invalid face index. Fixes #1138. * src/sfnt/sfobjs.c (sfnt_init_face), src/sfnt/sfwoff2.c (woff2_open_font): Check `face_index` before decrementing. --- src/sfnt/sfobjs.c | 2 +- src/sfnt/sfwoff2.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/sfnt/sfobjs.c b/src/sfnt/sfobjs.c index f9d4d3858..9771c35df 100644 --- a/src/sfnt/sfobjs.c +++ b/src/sfnt/sfobjs.c @@ -566,7 +566,7 @@ face_index = FT_ABS( face_instance_index ) & 0xFFFF; /* value -(N+1) requests information on index N */ - if ( face_instance_index < 0 ) + if ( face_instance_index < 0 && face_index > 0 ) face_index--; if ( face_index >= face->ttc_header.count ) diff --git a/src/sfnt/sfwoff2.c b/src/sfnt/sfwoff2.c index cb1e0664a..165b875e5 100644 --- a/src/sfnt/sfwoff2.c +++ b/src/sfnt/sfwoff2.c @@ -2085,7 +2085,7 @@ /* Validate requested face index. */ *num_faces = woff2.num_fonts; /* value -(N+1) requests information on index N */ - if ( *face_instance_index < 0 ) + if ( *face_instance_index < 0 && face_index > 0 ) face_index--; if ( face_index >= woff2.num_fonts )