From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40788) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyM69-0007nM-N3 for qemu-devel@nongnu.org; Tue, 20 Mar 2018 14:35:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eyM68-0005gv-Ql for qemu-devel@nongnu.org; Tue, 20 Mar 2018 14:35:01 -0400 References: <20180320173632.25480-1-kwolf@redhat.com> <20180320173632.25480-8-kwolf@redhat.com> From: Eric Blake Message-ID: <31ee5185-a503-5b51-0343-68dcdb0e28ad@redhat.com> Date: Tue, 20 Mar 2018 13:34:52 -0500 MIME-Version: 1.0 In-Reply-To: <20180320173632.25480-8-kwolf@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-2.12 07/12] parallels: Check maximum cluster size on create List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf , qemu-block@nongnu.org Cc: mreitz@redhat.com, den@openvz.org, jcody@redhat.com, berrange@redhat.com, qemu-devel@nongnu.org On 03/20/2018 12:36 PM, Kevin Wolf wrote: > It's unclear what the real maximum cluster size is for the Parallels > format, but let's at least make sure that we don't get integer > overflows in our .bdrv_co_create implementation. > > Signed-off-by: Kevin Wolf > --- > block/parallels.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/block/parallels.c b/block/parallels.c > index 2da5e56a9d..e4ca018c2e 100644 > --- a/block/parallels.c > +++ b/block/parallels.c > @@ -526,6 +526,11 @@ static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts, > cl_size = DEFAULT_CLUSTER_SIZE; > } > > + /* XXX What is the real limit here? This is an insanely large maximum. */ > + if (cl_size >= UINT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) { INT64_MAX is probably a saner starting point for the division... > + error_setg(errp, "Cluster size is too large"); > + return -EINVAL; > + } > if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) { since total_size still has to fit within off_t (63 bits, not 64) > error_setg(errp, "Image size is too large for this cluster size"); > return -E2BIG; > With that change, Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org