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Cc:     baolu.lu@linux.intel.com, David Woodhouse <dwmw2@infradead.org>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Jiang Liu <jiang.liu@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/intel: Fix memleak in intel_irq_remapping_alloc
To:     Dinghao Liu <dinghao.liu@zju.edu.cn>, kjlu@umn.edu
References: <20210102095029.29053-1-dinghao.liu@zju.edu.cn>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <18add30d-a830-c531-6fd2-58a1898b157f@linux.intel.com>
Date:   Sun, 3 Jan 2021 10:40:06 +0800
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Hi,

On 2021/1/2 17:50, Dinghao Liu wrote:
> When irq_domain_get_irq_data() or irqd_cfg() fails
> meanwhile i == 0, data allocated by kzalloc() has not
> been freed before returning, which leads to memleak.
> 
> Fixes: b106ee63abccb ("irq_remapping/vt-d: Enhance Intel IR driver to support hierarchical irqdomains")
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>   drivers/iommu/intel/irq_remapping.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c
> index aeffda92b10b..cdaeed36750f 100644
> --- a/drivers/iommu/intel/irq_remapping.c
> +++ b/drivers/iommu/intel/irq_remapping.c
> @@ -1354,6 +1354,8 @@ static int intel_irq_remapping_alloc(struct irq_domain *domain,
>   		irq_cfg = irqd_cfg(irq_data);
>   		if (!irq_data || !irq_cfg) {
>   			ret = -EINVAL;
> +			kfree(data);
> +			data = NULL;

Do you need to check (i == 0) here? @data will not be used anymore as it
goes to out branch, why setting it to NULL here?

Best regards,
baolu

>   			goto out_free_data;
>   		}
>   
>