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Re: Debian FEATURE: /home/loser is with permissions 755, default umask 0022


From: Seth Arnold <seth.arnold () canonical com>
Date: Thu, 8 Oct 2020 00:30:01 +0000

On Wed, Oct 07, 2020 at 04:09:59PM -0500, Bob Friesenhahn wrote:
Ubuntu Linux (a Debian derivative) has changed the default.  However, we
found that the Ubuntu default caused problems for us while building our
software, and so we changed them back.

Hello Bob, can you please share some details on this?

I expect Ubuntu home directories to be 755 by default:
https://wiki.ubuntu.com/SecurityTeam/Policies#Permissive_Home_Directory_Access

And while it is very difficult to say "the umask", given that every
process's umask setting depends upon the actions of not only itself but
also its nearest parent to use the umask(2) syscall, but:

$ grep ^UMASK /etc/login.defs
UMASK           022

$ systemctl show -p UMask '*' | sort -u

UMask=0022

I'd certainly expect the default settings to be a umask of 0022, there's a
variety of umasks on the systems I've got easy access to:

$ sudo grep -h Umask /proc/*/status | sort -u
Umask:  0000
Umask:  0002
Umask:  0022
Umask:  0077
Umask:  0777
$ sudo grep -h Umask /proc/*/status | sort -u
Umask:  0000
Umask:  0002
Umask:  0022
Umask:  0077
$ sudo grep -h Umask /proc/*/status | sort -u
Umask:  0000
Umask:  0002
Umask:  0022

Thanks

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