CVE-2026-31776 Linux内核ALSA ctxfi越界访问漏洞

#include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> // Concept PoC for CVE-2026-31776 // This PoC attempts to trigger the missing index handling in ALSA ctxfi // by interacting with the DSP device. // Note: Actual trigger requires specific hardware (hw20k2). #define DEVICE "/dev/snd/hwC0D0" // Example device path int main() { int fd; printf("[*] Attempting to open ALSA device...\n"); // Open the sound device fd = open(DEVICE, O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); return 1; } printf("[+] Device opened successfully.\n"); // In a real scenario, specific IOCTLs or mixer controls // related to SPDIF1 on hw20k2 would be manipulated here // to hit the daio_device_index() flaw. // The bug causes -EINVAL to be used as an array index. printf("[*] Triggering vulnerability logic flow...\n"); // Placeholder for the specific trigger logic // ioctl(fd, SPECIFIC_TRIGGER_CMD, ...); close(fd); printf("[*] Done.\n"); return 0; }