Permission denied error on /root/.bash_profile when running su command

Written by Claudio Kuenzler - 1 comments

Published on November 25th 2014 - Listed in Linux Shell

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On an Ubuntu 14 server I recently saw a strange error on stdout when I tried to launch a command as another user through "su -":

su - toto -m -c "/srv/tomcat/toto/bin/startup.sh"
-su: /root/.bash_profile: Permission denied
Using CATALINA_BASE:   /srv/tomcat/toto
Using CATALINA_HOME:   /srv/tomcat
Using CATALINA_TMPDIR: /srv/tomcat/toto/temp
Using JRE_HOME:        /srv/java
Using CLASSPATH:       /srv/tomcat/bin/bootstrap.jar:/srv/tomcat/bin/tomcat-juli.jar
Tomcat started.

Although the command worked and was successfully executed, I was wondering about the Permission denied error on /root/.bash_profile. To fully (or even partly) understand how bash handles different types of shells, you should take a look at "man bash" and grep for INVOCATION. There it is written black on white (or white on black in a standard console) - unfortunately not very clear though. Luckily I found the following graphic a while ago which explains which type of shell is loading which files (the printed version of it is hanging behind me in my office by the way).

Source: http://www.solipsys.co.uk/new/BashInitialisationFiles.html

Because the shell environment of root is kept by using the -m parameter (preserve environment) and because of the "su -" which is interpreted as a login shell, the shell environment tries to read first /etc/profile and then
/root/.bash_profile. But because toto user cannot access /root/.bash_profile there comes this permission denied error.

If the /root folder would allow permission to be read by the toto user, the same command works fine without any permission denied error:

chmod 755 /root
su - toto -m -c "/srv/tomcat/toto/bin/shutdown.sh"
Using CATALINA_BASE:   /srv/tomcat/toto
Using CATALINA_HOME:   /srv/tomcat
Using CATALINA_TMPDIR: /srv/tomcat/toto/temp
Using JRE_HOME:        /srv/java
Using CLASSPATH:       /srv/tomcat/bin/bootstrap.jar:/srv/tomcat/bin/tomcat-juli.jar

But granting access to /root is bad. There are other alternatives.
su can also be launched without a login shell (without the dash after su):

su toto -m -c "/srv/tomcat/toto/bin/startup.sh"
Using CATALINA_BASE:   /srv/tomcat/toto
Using CATALINA_HOME:   /srv/tomcat
Using CATALINA_TMPDIR: /srv/tomcat/toto/temp
Using JRE_HOME:        /srv/java
Using CLASSPATH:       /srv/tomcat/bin/bootstrap.jar:/srv/tomcat/bin/tomcat-juli.jar
Tomcat started.

When the same command is launched without the login shell, it just reads the $BASH_ENV from the current session (from root), without trying to load any other files (from /root). Hence no permission denied error.

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Comments (newest first)

Rafael Horacio from wrote on Jul 24th, 2020:

Thanks a lot, I had a similar error here

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