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

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf
> Of Byungchul Park
> Sent: Tuesday, December 16, 2025 5:07 AM
> To: netdev@xxxxxxxxxxxxxxx; kuba@xxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; kernel_team@xxxxxxxxxxx;
> harry.yoo@xxxxxxxxxx; david@xxxxxxxxxx; willy@xxxxxxxxxxxxx;
> toke@xxxxxxxxxx; asml.silence@xxxxxxxxx; almasrymina@xxxxxxxxxx;
> Nguyen, Anthony L <anthony.l.nguyen@xxxxxxxxx>; Kitszel, Przemyslaw
> <przemyslaw.kitszel@xxxxxxxxx>; andrew+netdev@xxxxxxx;
> davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; pabeni@xxxxxxxxxx; intel-
> wired-lan@xxxxxxxxxxxxxxxx
> 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@xxxxxx>
> ---
>  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?

> 
>  		if (ice_lbtest_check_frame(received_buf))
>  			valid_frames++;
> --
> 2.17.1