diff options
Diffstat (limited to 'src/hb-sanitize.hh')
| -rw-r--r-- | src/hb-sanitize.hh | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/src/hb-sanitize.hh b/src/hb-sanitize.hh index 2e536c7a8..bd3250e58 100644 --- a/src/hb-sanitize.hh +++ b/src/hb-sanitize.hh @@ -123,6 +123,7 @@ struct hb_sanitize_context_t : hb_sanitize_context_t () : start (nullptr), end (nullptr), max_ops (0), max_subtables (0), + recursion_depth (0), writable (false), edit_count (0), blob (nullptr), num_glyphs (65536), @@ -197,14 +198,16 @@ struct hb_sanitize_context_t : void start_processing () { reset_object (); - if (unlikely (hb_unsigned_mul_overflows (this->end - this->start, HB_SANITIZE_MAX_OPS_FACTOR))) + unsigned m; + if (unlikely (hb_unsigned_mul_overflows (this->end - this->start, HB_SANITIZE_MAX_OPS_FACTOR, &m))) this->max_ops = HB_SANITIZE_MAX_OPS_MAX; else - this->max_ops = hb_clamp ((unsigned) (this->end - this->start) * HB_SANITIZE_MAX_OPS_FACTOR, + this->max_ops = hb_clamp (m, (unsigned) HB_SANITIZE_MAX_OPS_MIN, (unsigned) HB_SANITIZE_MAX_OPS_MAX); this->edit_count = 0; this->debug_depth = 0; + this->recursion_depth = 0; DEBUG_MSG_LEVEL (SANITIZE, start, 0, +1, "start [%p..%p] (%lu bytes)", @@ -250,8 +253,9 @@ struct hb_sanitize_context_t : unsigned int a, unsigned int b) const { - return !hb_unsigned_mul_overflows (a, b) && - this->check_range (base, a * b); + unsigned m; + return !hb_unsigned_mul_overflows (a, b, &m) && + this->check_range (base, m); } template <typename T> @@ -260,8 +264,9 @@ struct hb_sanitize_context_t : unsigned int b, unsigned int c) const { - return !hb_unsigned_mul_overflows (a, b) && - this->check_range (base, a * b, c); + unsigned m; + return !hb_unsigned_mul_overflows (a, b, &m) && + this->check_range (base, m, c); } template <typename T> @@ -278,6 +283,18 @@ struct hb_sanitize_context_t : return this->check_range (base, a, b, hb_static_size (T)); } + bool check_start_recursion (int max_depth) + { + if (unlikely (recursion_depth >= max_depth)) return false; + return ++recursion_depth; + } + + bool end_recursion (bool result) + { + recursion_depth--; + return result; + } + template <typename Type> bool check_struct (const Type *obj) const { return likely (this->check_range (obj, obj->min_size)); } @@ -389,6 +406,7 @@ struct hb_sanitize_context_t : const char *start, *end; mutable int max_ops, max_subtables; private: + int recursion_depth; bool writable; unsigned int edit_count; hb_blob_t *blob; |