IB/mlx4: Fix error paths in mlx4_ib_create_flow()

The unwinding clean up code are err_create_flow starts at the current
index i.  That means we shouldn't increment i until we're really sure
we won't have to destroy the current flow; otherwise we might
increment the index, fail inside an is_bonded block, and end up
accessing off the end of the reg_id[] array.

This was detected by Coverity (CID 1271229).

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index cc64400..8191e17 100644 (file)
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -1185,7 +1185,6 @@ static struct ib_flow *mlx4_ib_create_flow(struct ib_qp *qp,
                                            &mflow->reg_id[i].id);
                if (err)
                        goto err_create_flow;
-               i++;
                if (is_bonded) {
                        /* Application always sees one port so the mirror rule
                         * must be on port #2
@@ -1200,6 +1199,7 @@ static struct ib_flow *mlx4_ib_create_flow(struct ib_qp *qp,
                        j++;
                }
 
+               i++;
        }
 
        if (i < ARRAY_SIZE(type) && flow_attr->type == IB_FLOW_ATTR_NORMAL) {
@@ -1207,7 +1207,7 @@ static struct ib_flow *mlx4_ib_create_flow(struct ib_qp *qp,
                                               &mflow->reg_id[i].id);
                if (err)
                        goto err_create_flow;
-               i++;
+
                if (is_bonded) {
                        flow_attr->port = 2;
                        err = mlx4_ib_tunnel_steer_add(qp, flow_attr,
@@ -1218,6 +1218,7 @@ static struct ib_flow *mlx4_ib_create_flow(struct ib_qp *qp,
                        j++;
                }
                /* function to create mirror rule */
+               i++;
        }
 
        return &mflow->ibflow;