Klemens Nanni 75d2080e53

Set groups when dropping privileges to not leak supplementary group access (#1202) ...

Changing the real and effective user/group IDs and the saved
set-user/group-ID is not enough to get rid of intial access permissions.

The list of groups must be cleared also, otherwise a process changing
from, e.g. `root:root` to `nobody:nobody` retains rights to access
`:wheel` files (assuming `root` is a member of the `wheel` group).

For example:
```
# id
uid=0(root) gid=0(wheel) groups=0(wheel), 2(kmem), 3(sys), 4(tty), 5(operator), 20(staff), 31(guest)
# ./yggdrasil -autoconf -logto /dev/null -user nobody &
[1] 4337
# ps -o command,user,group,supgrp -U nobody
COMMAND          USER     GROUP    SUPGRP
./yggdrasil -aut nobody   nobody   wheel,kmem,sys,tty,operator,staff,guest
```

Fix that so the process runs as mere
```
COMMAND          USER     GROUP    SUPGRP
./yggdrasil -aut nobody   nobody   nobody
```

Fixes #927.

2024-11-11 19:28:28 +00:00

..

chuser_other.go

argument to change uid/gid (#927)

2024-09-22 15:46:54 +00:00

chuser_unix.go

Set groups when dropping privileges to not leak supplementary group access (#1202)

2024-11-11 19:28:28 +00:00

main.go

update ironwood dependency

2024-09-28 18:52:04 -05:00