nfs_commonsubs.c: Add a sanity check for nid_ngroupHEADmain

The nfsuserd(8) daemon passes user credentials
(uid + gids) into the kernel for users and groups
identified by name (received from a NFSv4 server).

This patch add a sanity check for the number of
groups (nid_ngroup) passed in.

It's only purpose is to protect against a bogus
nfsuserd(8) running in a jail.

Reported by:	Ilja Van Sprundel <ivansprundel@ioactive.com>
Reviewed by:	markj
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D53389

0 files changed, 0 insertions, 0 deletions