From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58493) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XZN0M-0003tL-Ly for qemu-devel@nongnu.org; Wed, 01 Oct 2014 12:44:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XZN0G-0003JC-6o for qemu-devel@nongnu.org; Wed, 01 Oct 2014 12:43:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2812) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XZN0F-0003Ix-VT for qemu-devel@nongnu.org; Wed, 01 Oct 2014 12:43:48 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s91Ghldp013430 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 1 Oct 2014 12:43:47 -0400 From: Markus Armbruster Date: Wed, 1 Oct 2014 18:43:44 +0200 Message-Id: <1412181824-26936-1-git-send-email-armbru@redhat.com> Subject: [Qemu-devel] [PATCH] virtio-balloon: Tweak recent fix for integer overflow List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: lcapitulino@redhat.com Commit 1f9296b avoids "other kinds of overflow" by limiting the polling interval to UINT_MAX. The computations to protect are done in 64 bits. This is indeed safe when unsigned is 32 bits, as it commonly is. It isn't when unsigned is 64 bits. Purely theoretical; I'm not aware of such a system. Limit it to UINT32_MAX instead. Signed-off-by: Markus Armbruster --- hw/virtio/virtio-balloon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index b5cf7ca..7bfbb75 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -170,7 +170,7 @@ static void balloon_stats_set_poll_interval(Object *obj, struct Visitor *v, return; } - if (value > UINT_MAX) { + if (value > UINT32_MAX) { error_setg(errp, "timer value is too big"); return; } -- 1.9.3