From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51731) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XcEOs-0001Dz-Il for qemu-devel@nongnu.org; Thu, 09 Oct 2014 10:09:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XcEOm-0007yP-8t for qemu-devel@nongnu.org; Thu, 09 Oct 2014 10:09:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47311) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XcEOm-0007y9-1b for qemu-devel@nongnu.org; Thu, 09 Oct 2014 10:08:56 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s99E8sq1017475 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 9 Oct 2014 10:08:55 -0400 Date: Thu, 9 Oct 2014 09:49:37 -0400 From: Luiz Capitulino Message-ID: <20141009094937.129132f3@redhat.com> In-Reply-To: <1412181824-26936-1-git-send-email-armbru@redhat.com> References: <1412181824-26936-1-git-send-email-armbru@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] virtio-balloon: Tweak recent fix for integer overflow List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-devel@nongnu.org On Wed, 1 Oct 2014 18:43:44 +0200 Markus Armbruster wrote: > 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 Applied to the qmp branch, thanks. > --- > 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; > }