blob: 3335fbda064bdfd1b58e02d9a2d2f5e8f73a14d9 [file] [log] [blame]
From 53dfdcd8198d2b3201a23c4bad9190519ba918db Mon Sep 17 00:00:00 2001
From: Werner Lemberg <wl@gnu.org>
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.
Upstream-Status: Backport
https://gitlab.freedesktop.org/freetype/freetype/-/commit/53dfdcd8198d2b3201a23c4bad9190519ba918db
Signed-off-by: Davide Gardenal <davide.gardenal@huawei.com>
---
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 )
--
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