NetBSD 1.4 through 1.6 beta allows local users to cause a denial of service (kernel panic) via a series of calls to the TIOCSCTTY ioctl, wh…

NetBSD 1.4 through 1.6 beta allows local users to cause a denial of service (kernel panic) via a series of calls to the TIOCSCTTY ioctl, which causes an integer overflow in a structure counter and sets the counter to zero, which frees memory that is still in use by other processes.