PATH env var declared in /etc/environment not inherited?

Question

Working on Ubuntu 16.04.05.

According to the official debian and ubuntu documentations, variables declared therein should be inherited by all users;

Then how is the following explained:

root@pkara-pc01:~# cat /etc/environment 
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
root@pkara-pc01:~# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin

(i.e. paths in /etc/environment not ending up in root PATH) given that no explicit PATH override seems to take place in:

a) /root/.profile

root@pkara-pc01:~# grep -i path /root/.profile
root@pkara-pc01:~#

b) /root/.bashrc

root@pkara-pc01:~# grep -i path /root/.bashrc
root@pkara-pc01:~#

c) /etc/profile

root@pkara-pc01:~# grep -i path /etc/profile
root@pkara-pc01:~#

d) in /etc/profile.d/ there is only a PATH expansion to account for /snap/bin

root@pkara-pc01:~# grep -rniI -A 1 path /etc/profile.d/
/etc/profile.d/apps-bin-path.sh:3:# Expand $PATH to include the directory where snappy applications go.
/etc/profile.d/apps-bin-path.sh:4:if [ "${PATH#*/snap/bin}" = "${PATH}" ]; then
/etc/profile.d/apps-bin-path.sh:5:    export PATH=$PATH:/snap/bin
/etc/profile.d/apps-bin-path.sh-6-fi

Update:

Regarding relation to this issue as pointed out by @Kusalandra,

$ su -
Password: 
root@pkara-pc01:~# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin
root@pkara-pc01:~# exit
logout
/home/pkara/Workspace/gitlab/sonar-scanner
$ sudo -i
root@pkara-pc01:~# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin
root@pkara-pc01:~#

However:

root@pkara-pc01:~# grep -i secure_path /etc/sudoers
Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"

So it seems the secure_path is applied in both su and sudo cases? (which is not what the related issue states).

sudo may well set the PATH for root to some predetermined value or there may be some other security policy in place that changes the PATH from what's in /etc/environment. — Kusalananda, Aug 24 '18 at 12:28
This may be closely related: https://unix.stackexchange.com/questions/8646/why-are-path-variables-different-when-running-via-sudo-and-su — Kusalananda, Aug 24 '18 at 12:32

score 4 · Accepted Answer · answered Aug 24 '18 at 13:08

4

The default paths come from /etc/login.defs, which contains (in Debian at least, I suspect it’s the same in Ubuntu):

#
# *REQUIRED*  The default PATH settings, for superuser and normal users.
#
# (they are minimal, add the rest in the shell startup files)
ENV_SUPATH      PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
ENV_PATH        PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games

This is mentioned at the bottom of the Debian wiki page you linked to, in the context of su.

answered Aug 24 '18 at 13:08

Stephen Kitt

434,908

I modified ENV_SUPATH in Ubuntu 22.04, but sudo -s still shows an unmodified $PATH, any idea why? – bilogic Jul 13 '23 at 07:24
@bilogic login.defs is only taken into account for logins, you need to use sudo -i instead of sudo -s. – Stephen Kitt Jul 13 '23 at 09:59
there is yet another location, secure_path in /etc/sudoers, modifying it did the trick – bilogic Jul 13 '23 at 16:59
@bilogic yes, that’s mentioned in the question. – Stephen Kitt Jul 13 '23 at 18:02
Thanks, finally saw it, I missed it when looking from a) to d) – bilogic Jul 14 '23 at 04:26

PATH env var declared in /etc/environment not inherited?

1 Answers1