[PATCH net] net: stmmac: fix the crash issue for zero copy XDP_TX action

[Wei Fang]

> There is a crash issue when running zero copy XDP_TX action, the crash
> log is shown below.
> 
> [  216.122464] Unable to handle kernel paging request at virtual address
> fffeffff80000000
> [  216.187524] Internal error: Oops: 0000000096000144 [#1]  SMP
> [  216.301694] Call trace:
> [  216.304130]  dcache_clean_poc+0x20/0x38 (P)
> [  216.308308]  __dma_sync_single_for_device+0x1bc/0x1e0
> [  216.313351]  stmmac_xdp_xmit_xdpf+0x354/0x400
> [  216.317701]  __stmmac_xdp_run_prog+0x164/0x368
> [  216.322139]  stmmac_napi_poll_rxtx+0xba8/0xf00
> [  216.326576]  __napi_poll+0x40/0x218
> [  216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt
> 
> For XDP_TX action, the xdp_buff is converted to xdp_frame by
> xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame
> depends on the memory type of the xdp_buff. For page pool based xdp_buff
> it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero
> copy
> XSK pool based xdp_buff it produces xdp_frame with memory type
> MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not
> check the
> memory type and always uses the page pool type, this leads to invalid
> mappings and causes the crash. Therefore, check the xdp_buff memory type
> in stmmac_xdp_xmit_back() to fix this issue.
> 
> Fixes: bba2556efad6 ("net: stmmac: Enable RX via AF_XDP zero-copy")
> Signed-off-by: Wei Fang <wei.fang at nxp.com>
> ---
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c   | 17
> +++++++++++++++--

Hi,

Could this patch be applied?