Recent commits to the FreeBSD kernel (r334533 and r334534, which modified sys/libkern/memset.c) had apparently revealed a bug in the nVidia driver code (nvidia_get_card_info() function of nvidia_subr.c file). The following pseudo-patch fixes it:
struct nv_ioctl_card_info *ci; ... - memset(ci, 0, sizeof(ci)); + memset(ci, 0, sizeof(*ci));
See the following PR (aka bug report aka issue) for the details. I hope you guys could fix it in the next release(s). Thanks!