RE: [Intel-wired-lan] [PATCH iwl-net] idpf: protect shutdown from reset

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf
> Of Larysa Zaremba
> Sent: Thursday, April 10, 2025 1:52 PM
> To: intel-wired-lan@xxxxxxxxxxxxxxxx; Nguyen, Anthony L
> <anthony.l.nguyen@xxxxxxxxx>
> Cc: Zaremba, Larysa <larysa.zaremba@xxxxxxxxx>; Michal Swiatkowski
> <michal.swiatkowski@xxxxxxxxxxxxxxx>; Tantilov, Emil S
> <emil.s.tantilov@xxxxxxxxx>; Chittim, Madhu <madhu.chittim@xxxxxxxxx>;
> Hay, Joshua A <joshua.a.hay@xxxxxxxxx>; Kubiak, Michal
> <michal.kubiak@xxxxxxxxx>; Kitszel, Przemyslaw
> <przemyslaw.kitszel@xxxxxxxxx>; Andrew Lunn <andrew+netdev@xxxxxxx>;
> David S. Miller <davem@xxxxxxxxxxxxx>; Dumazet, Eric
> <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni
> <pabeni@xxxxxxxxxx>; Simon Horman <horms@xxxxxxxxxx>;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [Intel-wired-lan] [PATCH iwl-net] idpf: protect shutdown from
> reset
> 
> Before the referenced commit, the shutdown just called idpf_remove(),
> this way IDPF_REMOVE_IN_PROG was protecting us from the serv_task
> rescheduling reset. Without this flag set the shutdown process is
> vulnerable to HW reset or any other triggering conditions (such as
> default mailbox being destroyed).
> 
> When one of conditions checked in idpf_service_task becomes true,
> vc_event_task can be rescheduled during shutdown, this leads to
> accessing freed memory e.g. idpf_req_rel_vector_indexes() trying to
> read
> vport->q_vector_idxs. This in turn causes the system to become defunct
> during e.g. systemctl kexec.
> 
> Considering using IDPF_REMOVE_IN_PROG would lead to more heavy
> shutdown process, instead just cancel the serv_task before cancelling
> adapter->serv_task before cancelling adapter->vc_event_task to ensure
> adapter->that
> reset will not be scheduled while we are doing a shutdown.
> 
> Fixes: 4c9106f4906a ("idpf: fix adapter NULL pointer dereference on
> reboot")
> Reviewed-by: Michal Swiatkowski <michal.swiatkowski@xxxxxxxxxxxxxxx>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
> ---
>  drivers/net/ethernet/intel/idpf/idpf_main.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_main.c
> b/drivers/net/ethernet/intel/idpf/idpf_main.c
> index bec4a02c5373..b35713036a54 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_main.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_main.c
> @@ -89,6 +89,7 @@ static void idpf_shutdown(struct pci_dev *pdev)  {
>  	struct idpf_adapter *adapter = pci_get_drvdata(pdev);
> 
> +	cancel_delayed_work_sync(&adapter->serv_task);
>  	cancel_delayed_work_sync(&adapter->vc_event_task);
>  	idpf_vc_core_deinit(adapter);
>  	idpf_deinit_dflt_mbx(adapter);
> --
> 2.47.0

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@xxxxxxxxx>