Really shouldn't happen, but.
shadow-utils-4.0.3-23.06 from RHEL3 U5 HEAD
Add another "users" line to your /etc/group (so the entry is duplicated):
adduser -G users test
Check dmesg after a while (2 minutes in, and it was using around 300 megs of RAM):
Out of Memory: Killed process 28151 (adduser).
How do u add next entry? Did u edit /etc/group by hand?
It looks this problem affect all versions of shadow-utils.
I edited /etc/group by hand (a stupid mistake, but I would have expected adduser
to handle my error rather than to eat all my RAM).
Created attachment 112642 [details]