From: Prasad J Pandit <p...@fedoraproject.org> 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 <saaram...@gmail.com> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/rdma/rdma_backend.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) Update: No change, ack'd v1 -> https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02783.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; } -- 2.19.2
