[PATCH v6 20/37] cxlflash: Fix to prevent workq from accessing freed memory

2015-10-21 Thread Matthew R. Ochs
The workq can process work in parallel with a remove event, leading
to a condition where the workq handler can access freed memory.

To remedy, the workq should be terminated prior to freeing memory. Move
the termination call earlier in remove and use cancel_work_sync() instead
of flush_work() as there is not a need to process any scheduled work when
shutting down.

Signed-off-by: Matthew R. Ochs 
Signed-off-by: Manoj N. Kumar 
Reviewed-by: Brian King 
---
 drivers/scsi/cxlflash/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 6b8b159..d0b9972 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -736,11 +736,11 @@ static void cxlflash_remove(struct pci_dev *pdev)
/* Fall through */
case INIT_STATE_AFU:
term_afu(cfg);
+   cancel_work_sync(&cfg->work_q);
case INIT_STATE_PCI:
pci_release_regions(cfg->dev);
pci_disable_device(pdev);
case INIT_STATE_NONE:
-   flush_work(&cfg->work_q);
free_mem(cfg);
scsi_host_put(cfg->host);
break;
-- 
2.1.0

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Re: [PATCH v6 20/37] cxlflash: Fix to prevent workq from accessing freed memory

2015-10-23 Thread Tomas Henzl
On 21.10.2015 22:14, Matthew R. Ochs wrote:
> The workq can process work in parallel with a remove event, leading
> to a condition where the workq handler can access freed memory.
>
> To remedy, the workq should be terminated prior to freeing memory. Move
> the termination call earlier in remove and use cancel_work_sync() instead
> of flush_work() as there is not a need to process any scheduled work when
> shutting down.
>
> Signed-off-by: Matthew R. Ochs 
> Signed-off-by: Manoj N. Kumar 
> Reviewed-by: Brian King 

Reviewed-by: Tomas Henzl 

Tomas

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