Questions[umask](ubuntu)

I just found the following comment in /etc/login.defs:

# Enable setting of the umask group bits to be the same as owner bits
# (examples: 022 -> 002, 077 -> 007) for non-root users, if the uid is
# the same as gid, and username is the same as the primary group name.

This sounds cool, but it doesn't behave like that on my system:

me@mysystem ~ $ id
uid=1000(me) gid=1000(me) Gruppen=1000(me),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),100(users),113(lpadmin),130(sambashare),133(roccat)
me@mysystem ~ $ touch test
me@mysystem ~ $ ll test
-rw-r--r-- 1 me me 0 Aug 17 20:02 test
me@mysystem ~ $ rm test
me@mysystem ~ $ 

(following replacements were made (nothing else): my_real_user_and_groupname => me, my_real_hostname => mysystem)

My primary group is my personal group (as the group assignment of the test file shows), but I don't know a CLI command to check this. I checked it via GUI instead.

Anyone knows why the behaviour described in this comment does not affect my environment? Or cleaner: why is test created with -rw-r--r-- instead of -rw-rw-r-- on my system?

Update:

me@mysystem ~ $ cat .bashrc | grep -e umask -e UMASK
me@mysystem ~ $ cat .profile | grep -e umask -e UMASK
# the default umask is set in /etc/profile; for setting the umask
# for ssh logins, install and configure the libpam-umask package.
#umask 022
me@mysystem ~ $ cat /etc/profile | grep -e umask -e UMASK
me@mysystem ~ $ cat /etc/bash.bashrc | grep -e umask -e UMASK
me@mysystem ~ $ umask 
0022
me@mysystem ~ $ 

Update 2

me@mysystem / $ grep -r 'umask [0-9]' /etc/ 2> /dev/null
/etc/init/ssh.conf:umask 022
/etc/ppp/ip-down.d/0dns-down:umask 022
/etc/ppp/ip-up.d/0dns-up:umask 022
/etc/dhcp/dhclient-enter-hooks.d/samba: umask 022
/etc/init.d/umountfs:umask 022
/etc/init.d/ssh:umask 022
/etc/init.d/resolvconf: umask 022
/etc/init.d/urandom:    umask 077
/etc/init.d/urandom:    umask 022
/etc/init.d/urandom:    umask 077
/etc/init.d/rc:umask 022
/etc/skel/.profile:#umask 022
/etc/X11/Xsession:if (umask 077 && touch "$ERRFILE") 2> /dev/null && [ -w "$ERRFILE" ] &&
me@mysystem / $ 

I know that setting umask to 000 causes potential security issues. I don't care. I only want to know if something bad happens if I do it as root (sudo umask 000), or in /etc/init.d/rc script. By something bad, I mean breaking packages or essential parts of the system.

What command can you use to quickly find which file on your home folder containing the umask command?

$ grep -rnw "umask" ~

When I login anew my umask is 002. At least for a while. Then at some point, and I'm not sure when, it reverts to 000. This is very inconvenient and I'm now constantly living in fear of dropping files and folders with strange permissions across my home directory.

The reversion to 000 can happen after minutes of use, or after days. A few weeks after I first installed ubuntu it happened quite a lot, then it cooled down, and just in the last few days this issue has reared its ugly head again.

I can set it back to 002 with $ umask 002 but this only works for the current shell (as expected).

Some more information:

• The tty at ctrl-alt-f2 has a umask of 002 even when my f7 login is at 000
• /etc/profile says that umask is now handled by pam_umask
• /etc/login.defs has UMASK 022 and USERGROUPS_ENAB yes

I'm running Ubuntu 13.10 with XMonad and (oh-my-)zsh.

In case this is useful, here's my /etc/fstab

# <file system> <mount point>   <type>  <options>       <dump>  <pass>                                    
# / was on /dev/sdb8 during installation                                                                  
UUID=96f989e0-ee94-4bff-9663-3fa479a83ad4 /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sdb1 during installation                                                          
UUID=7682-B8AD  /boot/efi       vfat    defaults        0       1
# swap was on /dev/sdb7 during installation                                                               
UUID=0d7d57af-9a31-481e-9da4-1032c94f57e9 none            swap    sw              0       0

Here is an abridged version of my crontab from crontab -l

* * * * * cd /home/miles/code/Checkin/ && ./node_modules/.bin/coffee ./client.coffee -n attercop -h secret1.com -p 8888
* * * * * cd /home/miles/code/Checkin/ && ./node_modules/.bin/coffee ./client.coffee -n attercop -h secret2.com -p 8888

client.coffee is just a script that sends an http request.

And my root crontab from sudo crontab -l reports no crontab for root

I'm using umask 077 ."Other" and "group" do not have any rights, but the user can't execute files/directories. Why does umask 077 not allow the owner to execute files/directories?