[PATCH 1/3] net/ice: check for null before dereferencing

[Ciara Loftus]

When commiting a new Tx scheduler hierarchy we assume the user has
created a root node. However if they have not, it leads to an invalid
memory access. While this would be an invalid configuration by the user
we should still prevent the invalid memory access from happening. Do so
by ensuring the root node is non null before dereferencing.

Fixes: 715d449a965b ("net/ice: enhance Tx scheduler hierarchy support")
Cc: stable at dpdk.org

Signed-off-by: Ciara Loftus <ciara.loftus at intel.com>
---
 drivers/net/intel/ice/ice_tm.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/intel/ice/ice_tm.c b/drivers/net/intel/ice/ice_tm.c
index f2d8e12181..db895613cc 100644
--- a/drivers/net/intel/ice/ice_tm.c
+++ b/drivers/net/intel/ice/ice_tm.c
@@ -816,8 +816,13 @@ commit_new_hierarchy(struct rte_eth_dev *dev)
 	uint16_t nodes_created_per_level[ICE_TM_MAX_LAYERS] = {0};
 	uint8_t q_lvl = ice_get_leaf_level(pf);
 	uint8_t qg_lvl = q_lvl - 1;
-
 	struct ice_sched_node *new_vsi_root = hw->vsi_ctx[pf->main_vsi->idx]->sched.vsi_node[0];
+
+	if (sw_root == NULL) {
+		PMD_DRV_LOG(ERR, "No root node defined in TM hierarchy");
+		return -1;
+	}
+
 	/* handle case where VSI node needs to move DOWN the hierarchy */
 	while (new_vsi_root->tx_sched_layer < new_root_level) {
 		if (new_vsi_root->num_children == 0)
-- 
2.43.0