On Wed, Dec 12, 2018 at 05:17:21PM +0530, P J P wrote:
> From: Prasad J Pandit <pjp@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 <saaramar5@gmail.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
> 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 <yuval.shaia@oracle.com>
>
> --
> 2.19.2
>