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From: Joerg Roedel <joro@8bytes.org>
To: xkernel.wang@foxmail.com
Cc: agross@kernel.org, bjorn.andersson@linaro.org, will@kernel.org,
	linux-arm-msm@vger.kernel.org, iommu@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/msm: add a check for the return of kzalloc()
Date: Thu, 28 Apr 2022 10:03:58 +0200	[thread overview]
Message-ID: <YmpKbu4NOIHLQsvW@8bytes.org> (raw)
In-Reply-To: <tencent_6A5CCC9FB9221C4A1414E1534A3DFFC62008@qq.com>

On Fri, Mar 25, 2022 at 10:08:01AM +0800, xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> kzalloc() is a memory allocation function which can return NULL when
> some internal memory errors happen. So it is better to check it to
> prevent potential wrong memory access.
> 
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
>  drivers/iommu/msm_iommu.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 3a38352..697ad63 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -597,6 +597,10 @@ static void insert_iommu_master(struct device *dev,
>  
>  	if (list_empty(&(*iommu)->ctx_list)) {
>  		master = kzalloc(sizeof(*master), GFP_ATOMIC);
> +		if (!master) {
> +			dev_err(dev, "Failed to allocate iommu_master\n");
> +			return;
> +		}

This is not enough, if the error happens it also need to be propagated
to the caller.

Regards,

	Joerg

WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: xkernel.wang@foxmail.com
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
	iommu@lists.linux-foundation.org, agross@kernel.org,
	will@kernel.org
Subject: Re: [PATCH] iommu/msm: add a check for the return of kzalloc()
Date: Thu, 28 Apr 2022 10:03:58 +0200	[thread overview]
Message-ID: <YmpKbu4NOIHLQsvW@8bytes.org> (raw)
In-Reply-To: <tencent_6A5CCC9FB9221C4A1414E1534A3DFFC62008@qq.com>

On Fri, Mar 25, 2022 at 10:08:01AM +0800, xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> kzalloc() is a memory allocation function which can return NULL when
> some internal memory errors happen. So it is better to check it to
> prevent potential wrong memory access.
> 
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
>  drivers/iommu/msm_iommu.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 3a38352..697ad63 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -597,6 +597,10 @@ static void insert_iommu_master(struct device *dev,
>  
>  	if (list_empty(&(*iommu)->ctx_list)) {
>  		master = kzalloc(sizeof(*master), GFP_ATOMIC);
> +		if (!master) {
> +			dev_err(dev, "Failed to allocate iommu_master\n");
> +			return;
> +		}

This is not enough, if the error happens it also need to be propagated
to the caller.

Regards,

	Joerg
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2022-04-28  8:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-25  2:08 [PATCH] iommu/msm: add a check for the return of kzalloc() xkernel.wang
2022-03-25  2:08 ` xkernel.wang
2022-04-28  8:03 ` Joerg Roedel [this message]
2022-04-28  8:03   ` Joerg Roedel
2022-04-28 14:51 ` Jeffrey Hugo
2022-04-28 14:51   ` Jeffrey Hugo

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