[PATCH iwl-net 2/2] idpf: fix idpf_vc_core_init error path

[Pavan Kumar Linga <pavan.kumar.linga@intel.com>]

In an event where the platform running the device control plane
is rebooted, reset is detected on the driver. It releases
all the resources and waits for the reset to complete. Once the
reset is done, it tries to build the resources back. At this
time if the device control plane is not yet started, then
the driver timeouts on the virtchnl message and retries to
establish the mailbox again.

In the retry flow, mailbox is deinitialized but the mailbox
workqueue is still alive and polling for the mailbox message.
This results in accessing the released control queue leading to
null-ptr-deref. Fix it by unrolling the work queue cancellation
and mailbox deinitialization in the order which they got
initialized.

Also remove the redundant scheduling of the mailbox task in
idpf_vc_core_init.

Fixes: 4930fbf419a7 ("idpf: add core init and interrupt request")
Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
Cc: stable@vger.kernel.org # 6.9+
Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf_lib.c      | 1 +
 drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 7 -------
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index c3848e10e7db..b4fbb99bfad2 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -1786,6 +1786,7 @@ static int idpf_init_hard_reset(struct idpf_adapter *adapter)
 	 */
 	err = idpf_vc_core_init(adapter);
 	if (err) {
+		cancel_delayed_work_sync(&adapter->mbx_task);
 		idpf_deinit_dflt_mbx(adapter);
 		goto unlock_mutex;
 	}
diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
index 3be883726b87..d77d6c3805e2 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
@@ -3017,11 +3017,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
 		goto err_netdev_alloc;
 	}
 
-	/* Start the mailbox task before requesting vectors. This will ensure
-	 * vector information response from mailbox is handled
-	 */
-	queue_delayed_work(adapter->mbx_wq, &adapter->mbx_task, 0);
-
 	queue_delayed_work(adapter->serv_wq, &adapter->serv_task,
 			   msecs_to_jiffies(5 * (adapter->pdev->devfn & 0x07)));
 
@@ -3046,7 +3041,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
 
 err_intr_req:
 	cancel_delayed_work_sync(&adapter->serv_task);
-	cancel_delayed_work_sync(&adapter->mbx_task);
 	idpf_vport_params_buf_rel(adapter);
 err_netdev_alloc:
 	kfree(adapter->vports);
@@ -3070,7 +3064,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
 	adapter->state = __IDPF_VER_CHECK;
 	if (adapter->vcxn_mngr)
 		idpf_vc_xn_shutdown(adapter->vcxn_mngr);
-	idpf_deinit_dflt_mbx(adapter);
 	set_bit(IDPF_HR_DRV_LOAD, adapter->flags);
 	queue_delayed_work(adapter->vc_event_wq, &adapter->vc_event_task,
 			   msecs_to_jiffies(task_delay));
-- 
2.43.0