[PATCH 2/2] iommu: fix smmu initialization memory leak problem

[Will Deacon]

On Fri, Oct 21, 2022 at 11:51:47AM +0800, Longfang Liu wrote:
> When iommu_device_register() in arm_smmu_device_probe() fails,
> in addition to sysfs needs to be deleted, device should also
> be disabled, and the memory of iopf needs to be released to
> prevent memory leak of iopf.
> 
> Signed-off-by: Longfang Liu <liulongfang at huawei.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index a1db07bed6a9..c70defb0c866 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -3816,11 +3816,16 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>  	ret = iommu_device_register(&smmu->iommu, &arm_smmu_ops, dev);
>  	if (ret) {
>  		dev_err(dev, "Failed to register iommu\n");
> -		iommu_device_sysfs_remove(&smmu->iommu);
> -		return ret;
> +		goto err_sysfs_remove;
>  	}
>  
>  	return 0;
> +
> +err_sysfs_remove:
> +	iommu_device_sysfs_remove(&smmu->iommu);
> +	arm_smmu_device_disable(smmu);
> +	iopf_queue_free(smmu->evtq.iopf);
> +	return ret;

Doesn't this miss the cases where iommu_device_sysfs_add() or
arm_smmu_device_reset() fail?

We'd probably be better off using something like devres_alloc() to track
the iopf queue here.

Will