2023-11-27 06:36:44

by Kunwu Chan

[permalink] [raw]
Subject: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
Signed-off-by: Kunwu Chan <[email protected]>
---
drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
index 0b427fc24a96..59bbe5e13f6b 100644
--- a/drivers/platform/mellanox/mlxbf-pmc.c
+++ b/drivers/platform/mellanox/mlxbf-pmc.c
@@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct device *dev, int blk_num)
pmc->block[blk_num].block_attr_grp.attrs = pmc->block[blk_num].block_attr;
pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
dev, GFP_KERNEL, pmc->block_name[blk_num]);
+ if (!pmc->block[blk_num].block_attr_grp.name)
+ return -ENOMEM;
pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
pmc->group_num++;

--
2.34.1


2023-11-27 12:24:33

by Hans de Goede

[permalink] [raw]
Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

Hi,

On 11/27/23 07:34, Kunwu Chan wrote:
> devm_kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
>
> Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
> Signed-off-by: Kunwu Chan <[email protected]>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <[email protected]>

Regards,

Hans


> ---
> drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
> index 0b427fc24a96..59bbe5e13f6b 100644
> --- a/drivers/platform/mellanox/mlxbf-pmc.c
> +++ b/drivers/platform/mellanox/mlxbf-pmc.c
> @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct device *dev, int blk_num)
> pmc->block[blk_num].block_attr_grp.attrs = pmc->block[blk_num].block_attr;
> pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
> dev, GFP_KERNEL, pmc->block_name[blk_num]);
> + if (!pmc->block[blk_num].block_attr_grp.name)
> + return -ENOMEM;
> pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
> pmc->group_num++;
>

2023-11-28 09:51:44

by Ilpo Järvinen

[permalink] [raw]
Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

On Mon, 27 Nov 2023, Kunwu Chan wrote:

> devm_kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure.
>
> Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
> Signed-off-by: Kunwu Chan <[email protected]>
> ---
> drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
> index 0b427fc24a96..59bbe5e13f6b 100644
> --- a/drivers/platform/mellanox/mlxbf-pmc.c
> +++ b/drivers/platform/mellanox/mlxbf-pmc.c
> @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct device *dev, int blk_num)
> pmc->block[blk_num].block_attr_grp.attrs = pmc->block[blk_num].block_attr;
> pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
> dev, GFP_KERNEL, pmc->block_name[blk_num]);
> + if (!pmc->block[blk_num].block_attr_grp.name)
> + return -ENOMEM;
> pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
> pmc->group_num++;

I'm totally lost, why did you fix only one devm_kasprintf() location?
Don't all of them need this check?

--
i.

2023-11-30 09:44:02

by Kunwu Chan

[permalink] [raw]
Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

Thanks for your reply.

Cause i don't know how to deal with in some scenario,such as in
'mlxbf_pmc_init_perftype_counter', when 'attr->dev_attr.attr.name' is
null, should return '-ENOMEM' or 'continue' the loop?

So I'm going to solve it one by one.

Thanks again,
Kunwu

On 2023/11/28 17:51, Ilpo Järvinen wrote:
> On Mon, 27 Nov 2023, Kunwu Chan wrote:
>
>> devm_kasprintf() returns a pointer to dynamically allocated memory
>> which can be NULL upon failure.
>>
>> Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
>> Signed-off-by: Kunwu Chan <[email protected]>
>> ---
>> drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
>> index 0b427fc24a96..59bbe5e13f6b 100644
>> --- a/drivers/platform/mellanox/mlxbf-pmc.c
>> +++ b/drivers/platform/mellanox/mlxbf-pmc.c
>> @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct device *dev, int blk_num)
>> pmc->block[blk_num].block_attr_grp.attrs = pmc->block[blk_num].block_attr;
>> pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
>> dev, GFP_KERNEL, pmc->block_name[blk_num]);
>> + if (!pmc->block[blk_num].block_attr_grp.name)
>> + return -ENOMEM;
>> pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
>> pmc->group_num++;
>
> I'm totally lost, why did you fix only one devm_kasprintf() location?
> Don't all of them need this check?
>

2023-11-30 15:26:02

by Ilpo Järvinen

[permalink] [raw]
Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

Hi Vadim,

Could you please take a look at this and give advice to Kunwu so we can
get all of them squashed in one go.

On Thu, 30 Nov 2023, Kunwu Chan wrote:

> Thanks for your reply.
>
> Cause i don't know how to deal with in some scenario,such as in
> 'mlxbf_pmc_init_perftype_counter', when 'attr->dev_attr.attr.name' is null,
> should return '-ENOMEM' or 'continue' the loop?

I'd have thought returning -ENOMEM would be safe because it just ends up
failing probe()? ...And it's not that likely to occur in the first place.

--
i.

>
> So I'm going to solve it one by one.
>
> Thanks again,
> Kunwu
>
> On 2023/11/28 17:51, Ilpo Järvinen wrote:
> > On Mon, 27 Nov 2023, Kunwu Chan wrote:
> >
> > > devm_kasprintf() returns a pointer to dynamically allocated memory
> > > which can be NULL upon failure.
> > >
> > > Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField
> > > PMC driver")
> > > Signed-off-by: Kunwu Chan <[email protected]>
> > > ---
> > > drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/platform/mellanox/mlxbf-pmc.c
> > > b/drivers/platform/mellanox/mlxbf-pmc.c
> > > index 0b427fc24a96..59bbe5e13f6b 100644
> > > --- a/drivers/platform/mellanox/mlxbf-pmc.c
> > > +++ b/drivers/platform/mellanox/mlxbf-pmc.c
> > > @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct device
> > > *dev, int blk_num)
> > > pmc->block[blk_num].block_attr_grp.attrs =
> > > pmc->block[blk_num].block_attr;
> > > pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
> > > dev, GFP_KERNEL, pmc->block_name[blk_num]);
> > > + if (!pmc->block[blk_num].block_attr_grp.name)
> > > + return -ENOMEM;
> > > pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
> > > pmc->group_num++;
> >
> > I'm totally lost, why did you fix only one devm_kasprintf() location?
> > Don't all of them need this check?
> >
>

2023-11-30 16:02:26

by Vadim Pasternak

[permalink] [raw]
Subject: RE: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

Hi Ilpo!

> -----Original Message-----
> From: Ilpo Järvinen <[email protected]>
> Sent: Thursday, 30 November 2023 17:26
> To: Kunwu Chan <[email protected]>; Vadim Pasternak
> <[email protected]>
> Cc: Hans de Goede <[email protected]>; [email protected]; Shravan
> Ramani <[email protected]>; [email protected]; platform-
> [email protected]; LKML <[email protected]>
> Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in
> mlxbf_pmc_create_groups
>
> Hi Vadim,
>
> Could you please take a look at this and give advice to Kunwu so we can get all
> of them squashed in one go.

It seems there are six calls devm_kasprintf(), which requires checking pointer.

I guess, it is correct to return '-ENOMEM' for any failure.

I see there is another problem in mlxbf_pmc_probe() - it lacks error flow for:
pmc->hwmon_dev = devm_hwmon_device_register_with_groups(
dev, "bfperf", pmc, pmc->groups);

Need to add:
if (IS_ERR(pmc->hwmon_dev))
return PTR_ERR(pmc->hwmon_dev);

Sharvan, David,
Could you, please, have look?

>
> On Thu, 30 Nov 2023, Kunwu Chan wrote:
>
> > Thanks for your reply.
> >
> > Cause i don't know how to deal with in some scenario,such as in
> > 'mlxbf_pmc_init_perftype_counter', when 'attr->dev_attr.attr.name' is
> > null, should return '-ENOMEM' or 'continue' the loop?
>
> I'd have thought returning -ENOMEM would be safe because it just ends up
> failing probe()? ...And it's not that likely to occur in the first place.
>
> --
> i.
>
> >
> > So I'm going to solve it one by one.
> >
> > Thanks again,
> > Kunwu
> >
> > On 2023/11/28 17:51, Ilpo Järvinen wrote:
> > > On Mon, 27 Nov 2023, Kunwu Chan wrote:
> > >
> > > > devm_kasprintf() returns a pointer to dynamically allocated memory
> > > > which can be NULL upon failure.
> > > >
> > > > Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox
> > > > BlueField PMC driver")
> > > > Signed-off-by: Kunwu Chan <[email protected]>
> > > > ---
> > > > drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
> > > > 1 file changed, 2 insertions(+)
> > > >
> > > > diff --git a/drivers/platform/mellanox/mlxbf-pmc.c
> > > > b/drivers/platform/mellanox/mlxbf-pmc.c
> > > > index 0b427fc24a96..59bbe5e13f6b 100644
> > > > --- a/drivers/platform/mellanox/mlxbf-pmc.c
> > > > +++ b/drivers/platform/mellanox/mlxbf-pmc.c
> > > > @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct
> > > > device *dev, int blk_num)
> > > > pmc->block[blk_num].block_attr_grp.attrs =
> > > > pmc->block[blk_num].block_attr;
> > > > pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
> > > > dev, GFP_KERNEL, pmc->block_name[blk_num]);
> > > > + if (!pmc->block[blk_num].block_attr_grp.name)
> > > > + return -ENOMEM;
> > > > pmc->groups[pmc->group_num] = &pmc-
> >block[blk_num].block_attr_grp;
> > > > pmc->group_num++;
> > >
> > > I'm totally lost, why did you fix only one devm_kasprintf() location?
> > > Don't all of them need this check?
> > >
> >

2023-12-01 03:21:23

by Kunwu Chan

[permalink] [raw]
Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in mlxbf_pmc_create_groups

Hi Vadim,
Thanks for your reply.

I will follw your suggestions and add some ‘fixes’ label in v2 patch.

Thanks again,
Kunwu


On 2023/12/1 00:01, Vadim Pasternak wrote:
> Hi Ilpo!
>
>> -----Original Message-----
>> From: Ilpo Järvinen <[email protected]>
>> Sent: Thursday, 30 November 2023 17:26
>> To: Kunwu Chan <[email protected]>; Vadim Pasternak
>> <[email protected]>
>> Cc: Hans de Goede <[email protected]>; [email protected]; Shravan
>> Ramani <[email protected]>; [email protected]; platform-
>> [email protected]; LKML <[email protected]>
>> Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in
>> mlxbf_pmc_create_groups
>>
>> Hi Vadim,
>>
>> Could you please take a look at this and give advice to Kunwu so we can get all
>> of them squashed in one go.
>
> It seems there are six calls devm_kasprintf(), which requires checking pointer.
>
> I guess, it is correct to return '-ENOMEM' for any failure.
>
> I see there is another problem in mlxbf_pmc_probe() - it lacks error flow for:
> pmc->hwmon_dev = devm_hwmon_device_register_with_groups(
> dev, "bfperf", pmc, pmc->groups);
>
> Need to add:
> if (IS_ERR(pmc->hwmon_dev))
> return PTR_ERR(pmc->hwmon_dev);
>
> Sharvan, David,
> Could you, please, have look?
>
>>
>> On Thu, 30 Nov 2023, Kunwu Chan wrote:
>>
>>> Thanks for your reply.
>>>
>>> Cause i don't know how to deal with in some scenario,such as in
>>> 'mlxbf_pmc_init_perftype_counter', when 'attr->dev_attr.attr.name' is
>>> null, should return '-ENOMEM' or 'continue' the loop?
>>
>> I'd have thought returning -ENOMEM would be safe because it just ends up
>> failing probe()? ...And it's not that likely to occur in the first place.
>>
>> --
>> i.
>>
>>>
>>> So I'm going to solve it one by one.
>>>
>>> Thanks again,
>>> Kunwu
>>>
>>> On 2023/11/28 17:51, Ilpo Järvinen wrote:
>>>> On Mon, 27 Nov 2023, Kunwu Chan wrote:
>>>>
>>>>> devm_kasprintf() returns a pointer to dynamically allocated memory
>>>>> which can be NULL upon failure.
>>>>>
>>>>> Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox
>>>>> BlueField PMC driver")
>>>>> Signed-off-by: Kunwu Chan <[email protected]>
>>>>> ---
>>>>> drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
>>>>> 1 file changed, 2 insertions(+)
>>>>>
>>>>> diff --git a/drivers/platform/mellanox/mlxbf-pmc.c
>>>>> b/drivers/platform/mellanox/mlxbf-pmc.c
>>>>> index 0b427fc24a96..59bbe5e13f6b 100644
>>>>> --- a/drivers/platform/mellanox/mlxbf-pmc.c
>>>>> +++ b/drivers/platform/mellanox/mlxbf-pmc.c
>>>>> @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct
>>>>> device *dev, int blk_num)
>>>>> pmc->block[blk_num].block_attr_grp.attrs =
>>>>> pmc->block[blk_num].block_attr;
>>>>> pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
>>>>> dev, GFP_KERNEL, pmc->block_name[blk_num]);
>>>>> + if (!pmc->block[blk_num].block_attr_grp.name)
>>>>> + return -ENOMEM;
>>>>> pmc->groups[pmc->group_num] = &pmc-
>>> block[blk_num].block_attr_grp;
>>>>> pmc->group_num++;
>>>>
>>>> I'm totally lost, why did you fix only one devm_kasprintf() location?
>>>> Don't all of them need this check?
>>>>
>>>