From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49908) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiw8g-0001OY-P6 for qemu-devel@nongnu.org; Fri, 27 Jul 2018 02:22:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fiw8c-00055t-LB for qemu-devel@nongnu.org; Fri, 27 Jul 2018 02:22:10 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:34960 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fiw8c-000555-GV for qemu-devel@nongnu.org; Fri, 27 Jul 2018 02:22:06 -0400 From: Markus Armbruster Date: Fri, 27 Jul 2018 08:22:03 +0200 Message-Id: <20180727062204.10401-2-armbru@redhat.com> In-Reply-To: <20180727062204.10401-1-armbru@redhat.com> References: <20180727062204.10401-1-armbru@redhat.com> Subject: [Qemu-devel] [PATCH v2 1/2] qstring: Assert size calculations don't overflow List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: liujunjie23@huawei.com, eblake@redhat.com Signed-off-by: Markus Armbruster --- qobject/qstring.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/qobject/qstring.c b/qobject/qstring.c index 18b8eb82f8..1bb7784a88 100644 --- a/qobject/qstring.c +++ b/qobject/qstring.c @@ -41,17 +41,19 @@ QString *qstring_from_substr(const char *str, size_t start, size_t end) { QString *qstring; + assert(start <= end + 1); + qstring = g_malloc(sizeof(*qstring)); qobject_init(QOBJECT(qstring), QTYPE_QSTRING); qstring->length = end - start + 1; qstring->capacity = qstring->length; + assert(qstring->capacity < SIZE_MAX); qstring->string = g_malloc(qstring->capacity + 1); memcpy(qstring->string, str + start, qstring->length); qstring->string[qstring->length] = 0; - return qstring; } @@ -68,7 +70,9 @@ QString *qstring_from_str(const char *str) static void capacity_increase(QString *qstring, size_t len) { if (qstring->capacity < (qstring->length + len)) { + assert(len <= SIZE_MAX - qstring->capacity); qstring->capacity += len; + assert(qstring->capacity <= SIZE_MAX / 2); qstring->capacity *= 2; /* use exponential growth */ qstring->string = g_realloc(qstring->string, qstring->capacity + 1); -- 2.17.1