From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44001) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b7eCt-000587-NG for qemu-devel@nongnu.org; Tue, 31 May 2016 03:35:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b7eCs-0002bF-OY for qemu-devel@nongnu.org; Tue, 31 May 2016 03:35:19 -0400 Date: Tue, 31 May 2016 09:35:11 +0200 From: Kevin Wolf Message-ID: <20160531073511.GA4415@noname.redhat.com> References: <1464080368-29584-1-git-send-email-pl@kamp.de> <20160531064422.GA21877@ad.usersys.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160531064422.GA21877@ad.usersys.redhat.com> Subject: Re: [Qemu-devel] [Qemu-block] [PATCH] block/iscsi: avoid potential overflow of acb->task->cdb List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: Peter Lieven , pbonzini@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org, qemu-stable@nongnu.org Am 31.05.2016 um 08:44 hat Fam Zheng geschrieben: > On Tue, 05/24 10:59, Peter Lieven wrote: > > at least in the path via virtio-blk the maximum size is not > > restricted. > > > > Cc: qemu-stable@nongnu.org > > Signed-off-by: Peter Lieven > > --- > > block/iscsi.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/block/iscsi.c b/block/iscsi.c > > index 2ca8e72..e7d5f7b 100644 > > --- a/block/iscsi.c > > +++ b/block/iscsi.c > > @@ -833,6 +833,13 @@ static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs, > > return &acb->common; > > } > > > > + if (acb->ioh->cmd_len > SCSI_CDB_MAX_SIZE) { > > + error_report("iSCSI: ioctl error CDB exceeds max size (%d > %d)", > > + acb->ioh->cmd_len, SCSI_CDB_MAX_SIZE); > > + qemu_aio_unref(acb); > > + return NULL; > > + } > > + > > acb->task = malloc(sizeof(struct scsi_task)); > > if (acb->task == NULL) { > > error_report("iSCSI: Failed to allocate task for scsi command. %s", > > Is it better to invoke the cb and report -EINVAL to the caller? You need to implement the BH manually then. The difference is -EINVAL vs. -ENOTSUP, which don't result in a different guest behaviour. So I think returning NULL is simpler and therefore better. Kevin