From 335224beee2e72caab4ae56b76d6eb72001c3753 Mon Sep 17 00:00:00 2001 From: Ben Wagner Date: Thu, 3 Mar 2022 16:33:40 -0500 Subject: [PATCH] [sfnt] Fix bounds check in SVG. The `SVG_DOCUMENT_LIST_MINIMUM_SIZE` macro is non trivial and not protected by parentheses. As a result, the expression `table_size - SVG_DOCUMENT_LIST_MINIMUM_SIZE` expands to `table_size - 2U + SVG_DOCUMENT_RECORD_SIZE` instead of the expected `table_size - (2U + SVG_DOCUMENT_RECORD_SIZE)`. This causes an incorrect bounds check which may lead to reading past the end of the `SVG ` table. * src/sfnt/ttsvg.c (tt_face_load_svg): wrap macro definitions in parentheses. Bug: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=45179 --- src/sfnt/ttsvg.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/src/sfnt/ttsvg.c b/src/sfnt/ttsvg.c index 781a88b4d..cb70ee8b1 100644 --- a/src/sfnt/ttsvg.c +++ b/src/sfnt/ttsvg.c @@ -39,11 +39,11 @@ /* NOTE: These table sizes are given by the specification. */ -#define SVG_TABLE_HEADER_SIZE 10U -#define SVG_DOCUMENT_RECORD_SIZE 12U -#define SVG_DOCUMENT_LIST_MINIMUM_SIZE 2U + SVG_DOCUMENT_RECORD_SIZE -#define SVG_MINIMUM_SIZE SVG_TABLE_HEADER_SIZE + \ - SVG_DOCUMENT_LIST_MINIMUM_SIZE +#define SVG_TABLE_HEADER_SIZE (10U) +#define SVG_DOCUMENT_RECORD_SIZE (12U) +#define SVG_DOCUMENT_LIST_MINIMUM_SIZE (2U + SVG_DOCUMENT_RECORD_SIZE) +#define SVG_MINIMUM_SIZE (SVG_TABLE_HEADER_SIZE + \ + SVG_DOCUMENT_LIST_MINIMUM_SIZE) typedef struct Svg_