List PID of the respective User and Hide others

If you are using Linux kernel version 3.2+ (or RHEL/CentOS v6.5+ above) you can hide process from other users. Only root can see all process and user only see their own process. All you have to do is remount the /proc filesystem with the Linux kernel hardening hidepid option.

Say hello to hidepid option

This option defines how much info about processes we want to be available for non-owners. The values are as follows:

hidepid=0 – The old behavior – anybody may read all world-readable /proc/PID/* files (default).

hidepid=1 – It means users may not access any /proc// directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users.

hidepid=2 It means hidepid=1 plus all /proc/PID/ will be invisible to other users. It compicates intruder’s task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc.

Linux kernel protection: Hiding processes from other users

Type the following mount command:

# mount -o remount,rw,hidepid=2 /proc

Edit /etc/fstab, enter:

# vi /etc/fstab

Update/append/modify proc entry as follows so that protection get enabled automatically at server boot-time:

proc    /proc    proc    defaults,hidepid=2     0     0

Save and close the file.

$ ps -ef

$ sudo -s

# mount -o remount,rw,hidepid=2 /proc

$ ps -ef

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