From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43895) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gX31I-0003bv-N7 for qemu-devel@nongnu.org; Wed, 12 Dec 2018 06:49:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gX31E-00044S-O3 for qemu-devel@nongnu.org; Wed, 12 Dec 2018 06:49:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55156) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gX31E-00040d-GZ for qemu-devel@nongnu.org; Wed, 12 Dec 2018 06:49:36 -0500 From: P J P Date: Wed, 12 Dec 2018 17:17:21 +0530 Message-Id: <20181212114726.24060-2-ppandit@redhat.com> In-Reply-To: <20181212114726.24060-1-ppandit@redhat.com> References: <20181212114726.24060-1-ppandit@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [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: Yuval Shaia Cc: Qemu Developers , Marcel Apfelbaum , Saar Amar , Li Qiang , Prasad J Pandit From: Prasad J Pandit rdma back-end has scatter/gather array ibv_sge[MAX_SGE=3D4] 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_d= ev, } =20 pr_dbg("num_sge=3D%d\n", num_sge); - if (!num_sge) { - pr_dbg("num_sge=3D0\n"); - complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx); + if (!num_sge || num_sge > MAX_SGE) { + pr_dbg("invalid num_sge=3D%d\n", num_sge); + complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_INV_NUM_SGE, ctx); return; } =20 @@ -603,9 +603,9 @@ void rdma_backend_post_recv(RdmaBackendDev *backend_d= ev, } =20 pr_dbg("num_sge=3D%d\n", num_sge); - if (!num_sge) { - pr_dbg("num_sge=3D0\n"); - complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx); + if (!num_sge || num_sge > MAX_SGE) { + pr_dbg("invalid num_sge=3D%d\n", num_sge); + complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_INV_NUM_SGE, ctx); return; } =20 --=20 2.19.2