2023-04-13 03:36:18

by Zheng Wang

[permalink] [raw]
Subject: [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove due to race condition

In qedi_probe, it calls __qedi_probe, which bound &qedi->recovery_work
with qedi_recovery_handler and bound &qedi->board_disable_work
with qedi_board_disable_work.

When it calls qedi_schedule_recovery_handler, it will finally
call schedule_delayed_work to start the work.

When we call qedi_remove to remove the driver, there
may be a sequence as follows:

Fix it by finishing the work before cleanup in qedi_remove.

CPU0 CPU1

|qedi_recovery_handler
qedi_remove |
__qedi_remove |
iscsi_host_free |
scsi_host_put |
//free shost |
|iscsi_host_for_each_session
|//use qedi->shost

Fixes: 4b1068f5d74b ("scsi: qedi: Add MFW error recovery process")
Signed-off-by: Zheng Wang <[email protected]>
---
v2:
- remove unnecessary comment suggested by Mike Christie and cancel the work
after qedi_ops->stop and qedi_ops->ll2->stop which ensure there is no more
work suggested by Manish Rangankar
---
drivers/scsi/qedi/qedi_main.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index f2ee49756df8..45d359554182 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -2450,6 +2450,9 @@ static void __qedi_remove(struct pci_dev *pdev, int mode)
qedi_ops->ll2->stop(qedi->cdev);
}

+ cancel_delayed_work_sync(&qedi->recovery_work);
+ cancel_delayed_work_sync(&qedi->board_disable_work);
+
qedi_free_iscsi_pf_param(qedi);

rval = qedi_ops->common->update_drv_state(qedi->cdev, false);
--
2.25.1


2023-04-20 05:52:41

by Manish Rangankar

[permalink] [raw]
Subject: RE: [EXT] [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove due to race condition



> -----Original Message-----
> From: Zheng Wang <[email protected]>
> Sent: Thursday, April 13, 2023 9:04 AM
> To: Nilesh Javali <[email protected]>
> Cc: Manish Rangankar <[email protected]>; GR-QLogic-Storage-
> Upstream <[email protected]>;
> [email protected]; [email protected]; linux-
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; Zheng Wang <[email protected]>
> Subject: [EXT] [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove
> due to race condition
>
> External Email
>
> ----------------------------------------------------------------------
> In qedi_probe, it calls __qedi_probe, which bound &qedi->recovery_work
> with qedi_recovery_handler and bound &qedi->board_disable_work with
> qedi_board_disable_work.
>
> When it calls qedi_schedule_recovery_handler, it will finally call
> schedule_delayed_work to start the work.
>
> When we call qedi_remove to remove the driver, there may be a sequence
> as follows:
>
> Fix it by finishing the work before cleanup in qedi_remove.
>
> CPU0 CPU1
>
> |qedi_recovery_handler
> qedi_remove |
> __qedi_remove |
> iscsi_host_free |
> scsi_host_put |
> //free shost |
> |iscsi_host_for_each_session
> |//use qedi->shost
>
> Fixes: 4b1068f5d74b ("scsi: qedi: Add MFW error recovery process")
> Signed-off-by: Zheng Wang <[email protected]>
> ---
> v2:
> - remove unnecessary comment suggested by Mike Christie and cancel the
> work after qedi_ops->stop and qedi_ops->ll2->stop which ensure there is no
> more work suggested by Manish Rangankar
> ---
> drivers/scsi/qedi/qedi_main.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
> index f2ee49756df8..45d359554182 100644
> --- a/drivers/scsi/qedi/qedi_main.c
> +++ b/drivers/scsi/qedi/qedi_main.c
> @@ -2450,6 +2450,9 @@ static void __qedi_remove(struct pci_dev *pdev,
> int mode)
> qedi_ops->ll2->stop(qedi->cdev);
> }
>
> + cancel_delayed_work_sync(&qedi->recovery_work);
> + cancel_delayed_work_sync(&qedi->board_disable_work);
> +
> qedi_free_iscsi_pf_param(qedi);
>
> rval = qedi_ops->common->update_drv_state(qedi->cdev, false);
> --
> 2.25.1

Thanks,

Acked-by: Manish Rangankar <[email protected]>

2023-04-20 15:42:04

by Mike Christie

[permalink] [raw]
Subject: Re: [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove due to race condition

On 4/12/23 10:34 PM, Zheng Wang wrote:
> In qedi_probe, it calls __qedi_probe, which bound &qedi->recovery_work
> with qedi_recovery_handler and bound &qedi->board_disable_work
> with qedi_board_disable_work.
>
> When it calls qedi_schedule_recovery_handler, it will finally
> call schedule_delayed_work to start the work.
>
> When we call qedi_remove to remove the driver, there
> may be a sequence as follows:
>
> Fix it by finishing the work before cleanup in qedi_remove.
>
> CPU0 CPU1
>
> |qedi_recovery_handler
> qedi_remove |
> __qedi_remove |
> iscsi_host_free |
> scsi_host_put |
> //free shost |
> |iscsi_host_for_each_session
> |//use qedi->shost
>
> Fixes: 4b1068f5d74b ("scsi: qedi: Add MFW error recovery process")
> Signed-off-by: Zheng Wang <[email protected]>
> ---
> v2:
> - remove unnecessary comment suggested by Mike Christie and cancel the work
> after qedi_ops->stop and qedi_ops->ll2->stop which ensure there is no more
> work suggested by Manish Rangankar

Look ok to me now. Thanks.

Reviewed-by: Mike Christie <[email protected]>

2023-04-21 02:47:47

by Zheng Hacker

[permalink] [raw]
Subject: Re: [EXT] [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove due to race condition

Manish Rangankar <[email protected]> 于2023年4月20日周四 13:49写道:
>
>
>
> > -----Original Message-----
> > From: Zheng Wang <[email protected]>
> > Sent: Thursday, April 13, 2023 9:04 AM
> > To: Nilesh Javali <[email protected]>
> > Cc: Manish Rangankar <[email protected]>; GR-QLogic-Storage-
> > Upstream <[email protected]>;
> > [email protected]; [email protected]; linux-
> > [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; Zheng Wang <[email protected]>
> > Subject: [EXT] [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove
> > due to race condition
> >
> > External Email
> >
> > ----------------------------------------------------------------------
> > In qedi_probe, it calls __qedi_probe, which bound &qedi->recovery_work
> > with qedi_recovery_handler and bound &qedi->board_disable_work with
> > qedi_board_disable_work.
> >
> > When it calls qedi_schedule_recovery_handler, it will finally call
> > schedule_delayed_work to start the work.
> >
> > When we call qedi_remove to remove the driver, there may be a sequence
> > as follows:
> >
> > Fix it by finishing the work before cleanup in qedi_remove.
> >
> > CPU0 CPU1
> >
> > |qedi_recovery_handler
> > qedi_remove |
> > __qedi_remove |
> > iscsi_host_free |
> > scsi_host_put |
> > //free shost |
> > |iscsi_host_for_each_session
> > |//use qedi->shost
> >
> > Fixes: 4b1068f5d74b ("scsi: qedi: Add MFW error recovery process")
> > Signed-off-by: Zheng Wang <[email protected]>
> > ---
> > v2:
> > - remove unnecessary comment suggested by Mike Christie and cancel the
> > work after qedi_ops->stop and qedi_ops->ll2->stop which ensure there is no
> > more work suggested by Manish Rangankar
> > ---
> > drivers/scsi/qedi/qedi_main.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
> > index f2ee49756df8..45d359554182 100644
> > --- a/drivers/scsi/qedi/qedi_main.c
> > +++ b/drivers/scsi/qedi/qedi_main.c
> > @@ -2450,6 +2450,9 @@ static void __qedi_remove(struct pci_dev *pdev,
> > int mode)
> > qedi_ops->ll2->stop(qedi->cdev);
> > }
> >
> > + cancel_delayed_work_sync(&qedi->recovery_work);
> > + cancel_delayed_work_sync(&qedi->board_disable_work);
> > +
> > qedi_free_iscsi_pf_param(qedi);
> >
> > rval = qedi_ops->common->update_drv_state(qedi->cdev, false);
> > --
> > 2.25.1
>
> Thanks,
>
> Acked-by: Manish Rangankar <[email protected]>
>

Thanks for your review.

Best regards,
Zheng

2023-04-21 02:48:25

by Zheng Hacker

[permalink] [raw]
Subject: Re: [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove due to race condition

Mike Christie <[email protected]> 于2023年4月20日周四 23:39写道:
>
> On 4/12/23 10:34 PM, Zheng Wang wrote:
> > In qedi_probe, it calls __qedi_probe, which bound &qedi->recovery_work
> > with qedi_recovery_handler and bound &qedi->board_disable_work
> > with qedi_board_disable_work.
> >
> > When it calls qedi_schedule_recovery_handler, it will finally
> > call schedule_delayed_work to start the work.
> >
> > When we call qedi_remove to remove the driver, there
> > may be a sequence as follows:
> >
> > Fix it by finishing the work before cleanup in qedi_remove.
> >
> > CPU0 CPU1
> >
> > |qedi_recovery_handler
> > qedi_remove |
> > __qedi_remove |
> > iscsi_host_free |
> > scsi_host_put |
> > //free shost |
> > |iscsi_host_for_each_session
> > |//use qedi->shost
> >
> > Fixes: 4b1068f5d74b ("scsi: qedi: Add MFW error recovery process")
> > Signed-off-by: Zheng Wang <[email protected]>
> > ---
> > v2:
> > - remove unnecessary comment suggested by Mike Christie and cancel the work
> > after qedi_ops->stop and qedi_ops->ll2->stop which ensure there is no more
> > work suggested by Manish Rangankar
>
> Look ok to me now. Thanks.
>
> Reviewed-by: Mike Christie <[email protected]>

Thanks for your review.

Best regards,
Zheng

2023-04-25 03:41:28

by Martin K. Petersen

[permalink] [raw]
Subject: Re: [PATCH v2] scsi: qedi: Fix use after free bug in qedi_remove due to race condition


Zheng,

> In qedi_probe, it calls __qedi_probe, which bound &qedi->recovery_work
> with qedi_recovery_handler and bound &qedi->board_disable_work
> with qedi_board_disable_work.

Applied to 6.4/scsi-staging, thanks!

--
Martin K. Petersen Oracle Linux Engineering