The display driver allocattr functions in NetBSD 3.0 through 4.0_BETA2, and NetBSD-current before 20070728, allow local users to cause a denial of service (panic) via a (1) negative or (2) large value in an ioctl call, as demonstrated by the vga_allocattr function.
建议您更新当前系统或软件至最新版，完成漏洞的修复。