[PATCH v2 21/30] cxlflash: Fix to prevent workq from accessing freed memory
thenzl at redhat.com
Mon Sep 21 22:25:41 AEST 2015
On 16.9.2015 23:31, 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 <mrochs at linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj at linux.vnet.ibm.com>
> 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 1856a73..1625aea 100644
> --- a/drivers/scsi/cxlflash/main.c
> +++ b/drivers/scsi/cxlflash/main.c
> @@ -736,12 +736,12 @@ static void cxlflash_remove(struct pci_dev *pdev)
> /* Fall through */
> case INIT_STATE_AFU:
> + cancel_work_sync(&cfg->work_q);
You disable irqs after a call to cancel_work_sync.
That means a late int could trigger the workqueue again?
Please disable irqs earlier - as described in Documentation/PCI/pci.txt
> case INIT_STATE_PCI:
> case INIT_STATE_NONE:
> - flush_work(&cfg->work_q);
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