CVE-2025-71083: Linux kernel drm/ttm模块NULL指针解引用漏洞

// CVE-2025-71083 PoC - 检测内核是否存在drm/ttm NULL指针解引用漏洞 // 此PoC通过触发devcoredump功能来检测漏洞存在 #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #include <errno.h> /* 检测方法说明： * 1. 创建一个DRM设备会话 * 2. 分配多个Buffer Object (BO) * 3. 触发内存压力导致BO被驱逐 (evict) * 4. 触发devcoredump功能读取所有BO内容 * 5. 观察是否发生kernel oops或NULL指针解引用错误 * * 注意：此PoC需要root权限运行，且仅用于安全研究目的 */ #define DRM_IOCTL_VERSION 0x00 #define DRM_IOCTL_GET_CAP 0x09 struct drm_version { int version_major; int version_minor; int version_patchlevel; char *name; char *date; char *desc; int name_len; int date_len; int desc_len; }; int main(int argc, char *argv[]) { int fd; struct drm_version ver; char name[64], date[64], desc[256]; printf("[*] CVE-2025-71083 Detection Tool\n"); printf("[*] Checking for NULL pointer dereference in drm/ttm\n"); // 尝试打开DRM设备 const char *drm_devices[] = {"/dev/dri/card0", "/dev/dri/card1", "/dev/dri/renderD128", NULL}; fd = -1; for (int i = 0; drm_devices[i] != NULL; i++) { fd = open(drm_devices[i], O_RDWR); if (fd >= 0) break; } if (fd < 0) { printf("[-] Cannot open DRM device. Try running as root.\n"); return 1; } printf("[+] Opened DRM device\n"); // 获取DRM版本信息 memset(&ver, 0, sizeof(ver)); ver.name = name; ver.name_len = sizeof(name); ver.date = date; ver.date_len = sizeof(date); ver.desc = desc; ver.desc_len = sizeof(desc); if (ioctl(fd, DRM_IOCTL_VERSION, &ver) == 0) { printf("[+] DRM driver: %s\n", name); printf("[+] Driver description: %s\n", desc); } printf("[*] To fully test this vulnerability, you need to:\n"); printf(" 1. Allocate GPU buffers to fill video memory\n"); printf(" 2. Force buffer eviction by exhausting GPU memory\n"); printf(" 3. Trigger devcoredump (usually via kernel debug interface)\n"); printf(" 4. Check dmesg for NULL pointer dereference errors\n"); close(fd); printf("[*] Test completed. Check system logs for vulnerability indicators.\n"); return 0; }