[Intel-wired-lan] [PATCH net v3] i40e: Fix NULL ptr dereference on VSI filter sync

[Michał Małoszewski]

Remove the reason of null pointer dereference in sync vsi filters.
Added new I40E_VSI_RELEASING flag to signalize deleting and releasing
of VSI resources to sync this thread with sync filters subtask.
Without this patch it is possible to start update the vsi filter list
after vsi is removed, that's causing a kernel oops.

Fixes: 17652c6336fd("i40e: remove unused argument")
Signed-off-by: Grzegorz Szczurek <grzegorzx.szczurek at intel.com>
Signed-off by: Michal Maloszewski <michal.maloszewski at intel.com>
Reviewed-by: Przemyslaw Patynowski <przemyslawx.patynowski at intel.com>
Reviewed-by: Fijalkowski, WitoldX <witoldx.fijalkowski at intel.com>
Reviewed-by: Jaroslaw Gawin <jaroslawx.gawin at intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov at intel.com>
---
v3: removed features of other patches and changed permissions to 664
---
 drivers/net/ethernet/intel/i40e/i40e.h      | 1 +
 drivers/net/ethernet/intel/i40e/i40e_main.c | 5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index b6830e3..558b0ae 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -158,6 +158,7 @@ enum i40e_vsi_state_t {
 	__I40E_VSI_OVERFLOW_PROMISC,
 	__I40E_VSI_REINIT_REQUESTED,
 	__I40E_VSI_DOWN_REQUESTED,
+	__I40E_VSI_RELEASING,
 	/* This must be last as it determines the size of the BITMAP */
 	__I40E_VSI_STATE_SIZE__,
 };
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 3ed7f0e..c29678b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -2634,7 +2634,8 @@ static void i40e_sync_filters_subtask(struct i40e_pf *pf)
 
 	for (v = 0; v < pf->num_alloc_vsi; v++) {
 		if (pf->vsi[v] &&
-		    (pf->vsi[v]->flags & I40E_VSI_FLAG_FILTER_CHANGED)) {
+		    (pf->vsi[v]->flags & I40E_VSI_FLAG_FILTER_CHANGED) &&
+		    !test_bit(__I40E_VSI_RELEASING, pf->vsi[v]->state)) {
 			int ret = i40e_sync_vsi_filters(pf->vsi[v]);
 
 			if (ret) {
@@ -13787,7 +13788,7 @@ int i40e_vsi_release(struct i40e_vsi *vsi)
 		dev_info(&pf->pdev->dev, "Can't remove PF VSI\n");
 		return -ENODEV;
 	}
-
+	set_bit(__I40E_VSI_RELEASING, vsi->state);
 	uplink_seid = vsi->uplink_seid;
 	if (vsi->type != I40E_VSI_SRIOV) {
 		if (vsi->netdev_registered) {
-- 
1.8.3.1