Re: [Intel-wired-lan] [PATCH net-next] ice: access @pp through netmem_desc instead of page

[Pavel Begunkov <asml.silence@gmail.com>]

On 12/17/25 11:46, Loktionov, Aleksandr wrote:
> 
> 
>> -----Original Message-----
>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
>> Of Byungchul Park
>> Sent: Tuesday, December 16, 2025 5:07 AM
>> To: netdev@vger.kernel.org; kuba@kernel.org
>> Cc: linux-kernel@vger.kernel.org; kernel_team@skhynix.com;
>> harry.yoo@oracle.com; david@redhat.com; willy@infradead.org;
>> toke@redhat.com; asml.silence@gmail.com; almasrymina@google.com;
>> Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw
>> <przemyslaw.kitszel@intel.com>; andrew+netdev@lunn.ch;
>> davem@davemloft.net; edumazet@google.com; pabeni@redhat.com; intel-
>> wired-lan@lists.osuosl.org
>> Subject: [Intel-wired-lan] [PATCH net-next] ice: access @pp through
>> netmem_desc instead of page
>>
>> To eliminate the use of struct page in page pool, the page pool users
>> should use netmem descriptor and APIs instead.
>>
>> Make ice driver access @pp through netmem_desc instead of page.
>>
> Please add test info: HW/ASIC + PF/VF/SR-IOV, kernel version/branch, exact repro steps, before/after results (expected vs. observed).
> 
>> Signed-off-by: Byungchul Park <byungchul@sk.com>
>> ---
>>   drivers/net/ethernet/intel/ice/ice_ethtool.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c
>> b/drivers/net/ethernet/intel/ice/ice_ethtool.c
>> index 969d4f8f9c02..ae8a4e35cb10 100644
>> --- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
>> +++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
>> @@ -1251,7 +1251,7 @@ static int ice_lbtest_receive_frames(struct
>> ice_rx_ring *rx_ring)
>>   		rx_buf = &rx_ring->rx_fqes[i];
>>   		page = __netmem_to_page(rx_buf->netmem);
>>   		received_buf = page_address(page) + rx_buf->offset +
>> -			       page->pp->p.offset;
>> +			       pp_page_to_nmdesc(page)->pp->p.offset;
> If rx_buf->netmem is not backed by a page pool (e.g., fallback allocation), pp will be NULL and this dereferences NULL.
> I think the loopback test runs in a controlled environment, but the code must verify pp is valid before dereferencing.
> Isn't it?

Considering "page->pp->p.offset" poking into the pool, if that can
happen it's a pre-existing problem, which should be fixed first.

-- 
Pavel Begunkov