Re: [PATCH -next] ata: libata: Fix memory leak for error path in ata_host_alloc()

Re: [PATCH -next] ata: libata: Fix memory leak for error path in ata_host_alloc()

[Yu Kuai]

在 2024/08/16 11:58, Zheng Qixing 写道:
> In ata_host_alloc(), if ata_port_alloc(host) fails to allocate memory
> for a port, the allocated 'host' structure is not freed before returning
> from the function. This results in a potential memory leak.
> 
> This patch adds a kfree(host) before the error handling code is executed
> to ensure that the 'host' structure is properly freed in case of an
> allocation failure.
> 
> Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
> ---
>   drivers/ata/libata-core.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index e4023fc288ac..f27a18990c38 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -5663,8 +5663,10 @@ struct ata_host *ata_host_alloc(struct device *dev, int n_ports)
>   	}
>   
>   	dr = devres_alloc(ata_devres_release, 0, GFP_KERNEL);
> -	if (!dr)
> +	if (!dr) {
> +		kfree(host);
>   		goto err_out;
> +	}

Looks correct, dev_set_drvdata(dev, host) is not called yet.
ata_devres_release won't free host in this case.

I'll suggest to return NULL directly here, and then the 'err_out'
tag can be removed as well.

Anyway, with or without the cleanup:
Reviewed-by: Yu Kuai <yukuai3@huawei.com>

Thanks!
>   
>   	devres_add(dev, dr);
>   	dev_set_drvdata(dev, host);
> 

Re: [PATCH -next] ata: libata: Fix memory leak for error path in ata_host_alloc()

[Damien Le Moal]

On 8/16/24 15:42, Yu Kuai wrote:
> 在 2024/08/16 11:58, Zheng Qixing 写道:
>> In ata_host_alloc(), if ata_port_alloc(host) fails to allocate memory
>> for a port, the allocated 'host' structure is not freed before returning
>> from the function. This results in a potential memory leak.
>>
>> This patch adds a kfree(host) before the error handling code is executed
>> to ensure that the 'host' structure is properly freed in case of an
>> allocation failure.
>>
>> Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>

I did not receive this patch and I do not see it on the list either. Something
went wrong...
Can you resend please ? Thanks.

>> ---
>>   drivers/ata/libata-core.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>> index e4023fc288ac..f27a18990c38 100644
>> --- a/drivers/ata/libata-core.c
>> +++ b/drivers/ata/libata-core.c
>> @@ -5663,8 +5663,10 @@ struct ata_host *ata_host_alloc(struct device *dev, int n_ports)
>>   	}
>>   
>>   	dr = devres_alloc(ata_devres_release, 0, GFP_KERNEL);
>> -	if (!dr)
>> +	if (!dr) {
>> +		kfree(host);
>>   		goto err_out;
>> +	}
> 
> Looks correct, dev_set_drvdata(dev, host) is not called yet.
> ata_devres_release won't free host in this case.
> 
> I'll suggest to return NULL directly here, and then the 'err_out'
> tag can be removed as well.

I do not think so. Since devres_open_group() was called, need to call either
devres_remove_group() or devres_release_group().

> 
> Anyway, with or without the cleanup:
> Reviewed-by: Yu Kuai <yukuai3@huawei.com>>
> Thanks!
>>   
>>   	devres_add(dev, dr);
>>   	dev_set_drvdata(dev, host);
>>
> 

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH -next] ata: libata: Fix memory leak for error path in ata_host_alloc()

[Yu Kuai]

Hi,

在 2024/08/16 18:32, Damien Le Moal 写道:
> On 8/16/24 15:42, Yu Kuai wrote:
>> 在 2024/08/16 11:58, Zheng Qixing 写道:
>>> In ata_host_alloc(), if ata_port_alloc(host) fails to allocate memory
>>> for a port, the allocated 'host' structure is not freed before returning
>>> from the function. This results in a potential memory leak.
>>>
>>> This patch adds a kfree(host) before the error handling code is executed
>>> to ensure that the 'host' structure is properly freed in case of an
>>> allocation failure.
>>>
>>> Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
> 
> I did not receive this patch and I do not see it on the list either. Something
> went wrong...
> Can you resend please ? Thanks.
> 
>>> ---
>>>    drivers/ata/libata-core.c | 4 +++-
>>>    1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>>> index e4023fc288ac..f27a18990c38 100644
>>> --- a/drivers/ata/libata-core.c
>>> +++ b/drivers/ata/libata-core.c
>>> @@ -5663,8 +5663,10 @@ struct ata_host *ata_host_alloc(struct device *dev, int n_ports)
>>>    	}
>>>    
>>>    	dr = devres_alloc(ata_devres_release, 0, GFP_KERNEL);
>>> -	if (!dr)
>>> +	if (!dr) {
>>> +		kfree(host);
>>>    		goto err_out;
>>> +	}
>>
>> Looks correct, dev_set_drvdata(dev, host) is not called yet.
>> ata_devres_release won't free host in this case.
>>
>> I'll suggest to return NULL directly here, and then the 'err_out'
>> tag can be removed as well.
> 
> I do not think so. Since devres_open_group() was called, need to call either
> devres_remove_group() or devres_release_group().

Yes, you're right.

Thanks,
Kuai

> 
>>
>> Anyway, with or without the cleanup:
>> Reviewed-by: Yu Kuai <yukuai3@huawei.com>>
>> Thanks!
>>>    
>>>    	devres_add(dev, dr);
>>>    	dev_set_drvdata(dev, host);
>>>
>>
>