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Message-ID: <3231a5d7-29bc-4464-a26c-803b95774f86@kylinos.cn>
Date:   Mon, 11 Dec 2023 17:32:01 +0800
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User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] ice: Fix some null pointer dereference issues in
 ice_ptp.c
To:     Przemek Kitszel <przemyslaw.kitszel@intel.com>,
        jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, richardcochran@gmail.com,
        jacob.e.keller@intel.com, karol.kolacinski@intel.com
Cc:     michal.michalik@intel.com, intel-wired-lan@lists.osuosl.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Kunwu Chan <kunwu.chan@hotmail.com>
References: <20231211062649.247148-1-chentao@kylinos.cn>
 <447d130a-e1ac-02f6-e168-b04bfa9c6004@intel.com>
Content-Language: en-US
From:   Kunwu Chan <chentao@kylinos.cn>
In-Reply-To: <447d130a-e1ac-02f6-e168-b04bfa9c6004@intel.com>
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Thanks for your suggestion.

I made the patch based on linux-next.git(tag:next-20231211).

Our code is just self-similar, i didn't override the old name.
I keep the logic as it was before.
The newest code is:

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/intel/ice/ice_ptp.c#n2747

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/intel/ice/ice_ptp.c#n2993

I'll update v2 patch with:
1. update suject prefix to "[PATCH v2 iwl-next]"
2. remove 'dev_err'


Thanks again,
Kunwu

On 2023/12/11 15:15, Przemek Kitszel wrote:
> On 12/11/23 07:26, Kunwu Chan wrote:
>> devm_kasprintf() returns a pointer to dynamically allocated memory
>> which can be NULL upon failure.
>>
>> Fixes: d938a8cca88a ("ice: Auxbus devices & driver for E822 TS")
>> Cc: Kunwu Chan <kunwu.chan@hotmail.com>
>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
> 
> I would suggest adding "iwl-net" as a target here
> 
>> ---
>>   drivers/net/ethernet/intel/ice/ice_ptp.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c 
>> b/drivers/net/ethernet/intel/ice/ice_ptp.c
>> index 1eddcbe89b0c..59794ce4f243 100644
>> --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
>> +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
>> @@ -2668,6 +2668,8 @@ static int ice_ptp_register_auxbus_driver(struct 
>> ice_pf *pf)
>>       name = devm_kasprintf(dev, GFP_KERNEL, "ptp_aux_dev_%u_%u_clk%u",
>>                     pf->pdev->bus->number, PCI_SLOT(pf->pdev->devfn),
>>                     ice_get_ptp_src_clock_index(&pf->hw));
>> +    if (!name)
>> +        return -ENOMEM;
>>       aux_driver->name = name;
>>       aux_driver->shutdown = ice_ptp_auxbus_shutdown;
>> @@ -2929,6 +2931,10 @@ static int ice_ptp_create_auxbus_device(struct 
>> ice_pf *pf)
>>       name = devm_kasprintf(dev, GFP_KERNEL, "ptp_aux_dev_%u_%u_clk%u",
>>                     pf->pdev->bus->number, PCI_SLOT(pf->pdev->devfn),
>>                     ice_get_ptp_src_clock_index(&pf->hw));
>> +    if (!name) {
>> +        dev_err(dev, "Failed to allocate memory\n");
> 
> Kuba @ [1]:
> no warnings on allocation failures, there will be a splat for GFP_KERNEL
> (checkpatch should catch this)
> 
> [1] https://lore.kernel.org/netdev/20231206195304.6226771d@kernel.org/T/
> 
> so just "return -ENOMEM" would be sufficient
> 
>> +        return -ENOMEM;
>> +    }
>>       aux_dev->name = name;
>>       aux_dev->id = id;
> 
> I didn't checked but having same code in two places raises questions.
> Are you overwriting old name here, or our code is just self similar?