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A very serious security problem has been found in the Linux kernel. A 0-day local privilege escalation vulnerability has existed for eleven years since 2005. This bug affects all sort of of Android or Linux kernel to escalate privileges. Any user can become root in less than 5 seconds. The bug has existed since Linux kernel version 2.6.22+. How do I fix this problem?
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How to create snapshot in Linux KVM VM/Domain

Before upgrading my virtual machine, I would like to make a snapshot. I want to revert a domain/VM to a snapshot if something goes wrong with my upgrade. Is there a command to create a snapshot of virtual machine (VM) while it is running? Does qemu-kvm support live snapshot creation?
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cron Error: bad username; while reading /etc/cron.d file on Linux

I am getting the following error in my cron job log file /var/log/cron.log:
       Aug 22 01:59:01 server2 cron[7510]: Error: bad username; while reading /etc/cron.d/backups
I have job entry as follows to run a job at 00:50 every day for root user:
       50 0 * * * /etc/cron.d/backups
How do I fix this problem on Linux or Unix-like system?
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How to make disk image with dd on Linux or Unix

How do I create disk image using dd command? How do I perform disk cloning from a live Linux cd for backup or recovery purpose?
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How to configure a static IP address on CentOS 7 / RHEL 7

I am a new sysadmin and CentOS user. My system is configured to use DHCP. How can I switch from DHCP to static IP address configuration in a CentOS 7 desktop system? How do I setup a static TCP/IP address on my CentOS Linux 7 or Red Hat Enterprise Linux 7 server using command line option?
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How to see PCI devices info on CentOS 7 and RedHat Enterprise Linux 7

I wanted to see PCI devices information on my CentOS/RHEL 7 box. But, I’m getting an error that read as, “-bash: lspci: command not found”. How do I solve this problem and see PCI devices information on CentOS/RHEL 7?
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How to see CPU temperature on CentOS 7 and RedHat Enterprise Linux 7

I am a new sysadmin of CentOS 7 server. How do I get my CPU temperature Information on CentOS Linux 7 or Red Hat Enterprise Linux 7 server?
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Linux how long a process has been running?

I‘m a new Linux system user. How do I check how long a process or pid has been running on my Ubuntu Linux server?
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How to determine Linux guest VM virtualization technology

I have a cloud-based virtual machine running Ubuntu and CentOS Linux server. It may or may not be virtualized. How do I determine what kind of virtualization technology (VMWARE/ KVM/ XEN/ VirtualBox/ Container/ lxc/Hyper-V etc.) a Linux guest system running on? How do I find out the virtualization type of a CentOS 7 Linux VPS?
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Linux Iptables Delete postrouting Rule Command

I am a new Linux server sysadmin. I need to delete POSTROUTING rule. How do I delete postrouting rule on Linux server?
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