CVE-2025-71095: 
Linux Kernel vulnerability analysis and mitigation

In the Linux kernel, the following vulnerability has been resolved:

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

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.