From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53127) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gX7oT-0008Kn-Oc for qemu-devel@nongnu.org; Wed, 12 Dec 2018 11:56:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gX7oR-0005iF-0f for qemu-devel@nongnu.org; Wed, 12 Dec 2018 11:56:45 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:47488) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gX7oO-0005eI-QF for qemu-devel@nongnu.org; Wed, 12 Dec 2018 11:56:42 -0500 Date: Wed, 12 Dec 2018 18:56:11 +0200 From: Yuval Shaia Message-ID: <20181212165611.GA5948@lap1> References: <20181212114726.24060-1-ppandit@redhat.com> <20181212114726.24060-2-ppandit@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181212114726.24060-2-ppandit@redhat.com> Subject: Re: [Qemu-devel] [PATCH v1 1/6] rdma: check num_sge does not exceed MAX_SGE List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: P J P Cc: Qemu Developers , Marcel Apfelbaum , Saar Amar , Li Qiang , Prasad J Pandit , yuval.shaia@oracle.com On Wed, Dec 12, 2018 at 05:17:21PM +0530, P J P wrote: > From: Prasad J Pandit > > rdma back-end has scatter/gather array ibv_sge[MAX_SGE=4] set > to have 4 elements. A guest could send a 'PvrdmaSqWqe' ring element > with 'num_sge' set to > MAX_SGE, which may lead to OOB access issue. > Add check to avoid it. > > Reported-by: Saar Amar > Signed-off-by: Prasad J Pandit > --- > hw/rdma/rdma_backend.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > Update v1: use new error code VENDOR_ERR_INV_NUM_SGE > -> https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02220.html > > diff --git a/hw/rdma/rdma_backend.c b/hw/rdma/rdma_backend.c > index ae1e4dcb29..bd4710d16f 100644 > --- a/hw/rdma/rdma_backend.c > +++ b/hw/rdma/rdma_backend.c > @@ -476,9 +476,9 @@ void rdma_backend_post_send(RdmaBackendDev *backend_dev, > } > > pr_dbg("num_sge=%d\n", num_sge); > - if (!num_sge) { > - pr_dbg("num_sge=0\n"); > - complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx); > + if (!num_sge || num_sge > MAX_SGE) { > + pr_dbg("invalid num_sge=%d\n", num_sge); > + complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_INV_NUM_SGE, ctx); > return; > } > > @@ -603,9 +603,9 @@ void rdma_backend_post_recv(RdmaBackendDev *backend_dev, > } > > pr_dbg("num_sge=%d\n", num_sge); > - if (!num_sge) { > - pr_dbg("num_sge=0\n"); > - complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx); > + if (!num_sge || num_sge > MAX_SGE) { > + pr_dbg("invalid num_sge=%d\n", num_sge); > + complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_INV_NUM_SGE, ctx); > return; > } Reviewed-by: Yuval Shaia > > -- > 2.19.2 >