Re: [PATCH v2 1/2] dmaengine: idxd: Do not call destroy_workqueue with null idxd->wq

[Vinicius Costa Gomes]

Steve Wahl <steve.wahl@xxxxxxx> writes:

> Error paths within idxd_pci_probe_alloc and related functions end up
> calling destroy_workqueue with a null pointer, from
> idxd_conf_device_release via put_device, because that allocation has
> not yet occurred when the error is hit.
>
> This was encountered running in a kexec'd kdump kernel with reduced
> resources, causing the "Device is HALTED!" branch in
> idxd_device_init_reset to be taken.
>
> In idxd_conf_device_release, check that the workqueue has been
> allocated before trying to destroy it.
>
> Fixes: 3d33de353b1f ("dmaengine: idxd: Fix not releasing workqueue on .release()")
>
> Signed-off-by: Steve Wahl <steve.wahl@xxxxxxx>
> ---



> v2: split into two patches as requested by Vinicius Costa
>
>  drivers/dma/idxd/sysfs.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
> index 6d251095c350..d5ffc641c856 100644
> --- a/drivers/dma/idxd/sysfs.c
> +++ b/drivers/dma/idxd/sysfs.c
> @@ -1836,7 +1836,8 @@ static void idxd_conf_device_release(struct device *dev)
>  {
>  	struct idxd_device *idxd = confdev_to_idxd(dev);
>  
> -	destroy_workqueue(idxd->wq);
> +	if (idxd->wq)
> +		destroy_workqueue(idxd->wq);
>  	kfree(idxd->groups);
>  	bitmap_free(idxd->wq_enable_map);
>  	kfree(idxd->wqs);
> -- 
> 2.51.0
>

-- 
Vinicius