Re: [Intel-wired-lan] MMIO write access to an invalid page in i40e_clear_hw()

[Kyungwook Boo <bookyungwook@gmail.com>]

On 25. 3. 5. 21:11, Loktionov, Aleksandr wrote:
> 
> 
>> -----Original Message-----
>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
>> Przemek Kitszel
>> Sent: Wednesday, March 5, 2025 11:27 AM
>> To: Kyungwook Boo <bookyungwook@gmail.com>
>> Cc: intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org; Nguyen,
>> Anthony L <anthony.l.nguyen@intel.com>
>> Subject: Re: [Intel-wired-lan] MMIO write access to an invalid page in
>> i40e_clear_hw()
>>
>> On 3/3/25 11:19, Kyungwook Boo wrote:
>>> Hello,
>>>
>>> It seems that there are invalid page MMIO write access in
>>> i40e_clear_hw()
>>
>> Hi,
>>
>> is this something that actually occurred, or just a theoretical bug?
>> (depending on that we will apply it to different tree)
>>
>> please send a proper patch anyway, as it looks legit to don't go bananas when
>> HW gives you 0
>>
>> (and CC netdev instead of generic kernel ML, perhaps that's the reason this
>> mail was tagged as spam for me)

Hi,

thank you for your response.

If you’re asking whether this happened on a physical device, it did not, but it
is something that can be triggered through virtual device with fuzzed input.

Also, I'll follow your guidance when sending the proper patch.

>>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_common.c
>>> b/drivers/net/ethernet/intel/i40e/i40e_common.c
>>> index 370b4bddee44..97ef79be39b3 100644
>>> --- a/drivers/net/ethernet/intel/i40e/i40e_common.c
>>> +++ b/drivers/net/ethernet/intel/i40e/i40e_common.c
>>> @@ -848,19 +848,25 @@ void i40e_clear_hw(struct i40e_hw *hw)
>>>   	/* stop all the interrupts */
>>>   	wr32(hw, I40E_PFINT_ICR0_ENA, 0);
>>>   	val = 0x3 << I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT;
>>> -	for (i = 0; i < num_pf_int - 2; i++)
>>> -		wr32(hw, I40E_PFINT_DYN_CTLN(i), val);
>>> +	if (num_pf_int > 1) {
>>
>> instead of adding if conditions, I would simply change the type to be signed

I’ll incorporate the suggested approach when sending the patch.

Best,
Kyungwook Boo