[PATCH] bus: hisi_lpc: Don't use devm_kzalloc() to allocate logical PIO range

[PATCH] bus: hisi_lpc: Don't use devm_kzalloc() to allocate logical PIO range

[John Garry]

If, after registering a logical PIO range, the driver probe later fails,
the logical PIO range memory will be released automatically.

This causes an issue, in that the logical PIO range is not unregistered
(that is not supported) and the released range memory may be later
referenced

Allocate the logical PIO range with kzalloc() to avoid this potential
issue.

Fixes: adf38bb0b5956 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings")
Signed-off-by: John Garry <john.garry@huawei.com>

diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c
index 19d7b6ff2f17..d9ab4e76010d 100644
--- a/drivers/bus/hisi_lpc.c
+++ b/drivers/bus/hisi_lpc.c
@@ -599,7 +599,7 @@ static int hisi_lpc_probe(struct platform_device *pdev)
 	if (IS_ERR(lpcdev->membase))
 		return PTR_ERR(lpcdev->membase);
 
-	range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
+	range = kzalloc(sizeof(*range), GFP_KERNEL);
 	if (!range)
 		return -ENOMEM;
 
@@ -610,6 +610,7 @@ static int hisi_lpc_probe(struct platform_device *pdev)
 	ret = logic_pio_register_range(range);
 	if (ret) {
 		dev_err(dev, "register IO range failed (%d)!\n", ret);
+		kfree(range);
 		return ret;
 	}
 	lpcdev->io_host = range;
-- 
2.17.1

Re: [PATCH] bus: hisi_lpc: Don't use devm_kzalloc() to allocate logical PIO range

[Joe Perches]

On Fri, 2019-06-14 at 17:47 +0800, John Garry wrote:
> If, after registering a logical PIO range, the driver probe later fails,
> the logical PIO range memory will be released automatically.
> 
> This causes an issue, in that the logical PIO range is not unregistered
> (that is not supported) and the released range memory may be later
> referenced
> 
> Allocate the logical PIO range with kzalloc() to avoid this potential
> issue.
> 
> Fixes: adf38bb0b5956 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings")
> Signed-off-by: John Garry <john.garry@huawei.com>
> 
> diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c
[]
> @@ -599,7 +599,7 @@ static int hisi_lpc_probe(struct platform_device *pdev)
>  	if (IS_ERR(lpcdev->membase))
>  		return PTR_ERR(lpcdev->membase);
>  
> -	range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
> +	range = kzalloc(sizeof(*range), GFP_KERNEL);

If this is really necessary, it'd be useful to say so in the
code too with a comment so it doesn't get drive-by 'unfixed'
by someone well meaning but ill-uninformed.

Re: [PATCH] bus: hisi_lpc: Don't use devm_kzalloc() to allocate logical PIO range

[John Garry]

On 14/06/2019 11:04, Joe Perches wrote:
> On Fri, 2019-06-14 at 17:47 +0800, John Garry wrote:
>> If, after registering a logical PIO range, the driver probe later fails,
>> the logical PIO range memory will be released automatically.
>>
>> This causes an issue, in that the logical PIO range is not unregistered
>> (that is not supported) and the released range memory may be later
>> referenced
>>
>> Allocate the logical PIO range with kzalloc() to avoid this potential
>> issue.
>>
>> Fixes: adf38bb0b5956 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings")
>> Signed-off-by: John Garry <john.garry@huawei.com>
>>
>> diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c
> []
>> @@ -599,7 +599,7 @@ static int hisi_lpc_probe(struct platform_device *pdev)
>>  	if (IS_ERR(lpcdev->membase))
>>  		return PTR_ERR(lpcdev->membase);
>>
>> -	range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
>> +	range = kzalloc(sizeof(*range), GFP_KERNEL);
>
> If this is really necessary, it'd be useful to say so in the
> code too with a comment so it doesn't get drive-by 'unfixed'
> by someone well meaning but ill-uninformed.

OK, fine. I can do that.

Cheers,
John

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