-
Recent Posts
Recent Comments
- You can find my stuff on GitHub | cormander's blog on nagios snmp memory and swap plugin
- You can find my stuff on GitHub | cormander's blog on Monitor time drift with nagios and snmp
- You can find my stuff on GitHub | cormander's blog on nagios snmp check all disks plugin
- How to hook into (hijack) linux kernel functions via LKM | cormander's blog on What some (many?) people don’t understand about the GPL
- How I license code | cormander's blog on What some (many?) people don’t understand about the GPL
Archives
Categories
Meta
Category Archives: Linux
Repacking an RPM from files on the system
Have you ever had an RPM installed on the system that you needed installed on another system, but didn’t have the .rpm file for it? Or, have you wanted to make a .rpm file with just a minor change without … Continue reading
Posted in Fun, Linux
Leave a comment
nagios snmp check all disks plugin
Having to manage a wide array of servers with vastly different disk configurations, I found that things began to be very tedious with the nagios configuration file for disks checks. It seemed as if no two server disk configuration was … Continue reading
How to hook into (hijack) linux kernel functions via LKM
It’s about time I post a detailed explanation about how my tpe-lkm module is able to enforce its security policy. This post is very technical, readers beware. Note that this writeup is based on the code as it was the … Continue reading
Posted in Fun, ksplice, Linux, Security
Leave a comment
Monitor time drift with nagios and snmp
The other day I threw together a check_snmp_time.pl script that simply checks the remote’s time against the monitor host’s time. It’s fairly straight forward, and will alert you when host’s time drift too much, indicating that your ntpd configuration is … Continue reading
An agent, auditor, and bodyguard walk into a bar…
This evening I wasted a bunch of time on what turned out to be a simple problem. I really hate it when that happens. I fixed a bug in tpe-lkm where users weren’t seeing all of their processes, and updated … Continue reading
Posted in Complaints, Linux, nagios
Leave a comment
tpe-lkm “hardcoded_path” feature
This evening I implemented the optional hardcoded_path feature for tpe-lkm. It’s a way to be very strict on what on the system can be executed. When set, anything outside of the given path can’t be executed, regardless of permissions or … Continue reading
Posted in Linux, Security
Leave a comment
tpe-lkm “lock” sysctl feature
Tonight I implemented a “lock” sysctl feature for tpe-lkm. When enabled, the sysctl entries for the tpe module can’t be changed. It’s only real useful if also combined with the modules_disabled option.
Kidnapping a process’s pwd and root
This evening I wrote a chunk of code that, given a PID, goes and does the chdir() and chroot() calls on it to a given directory. That process suddenly finds itself isolated while it’s running. It’s kind of like pulling … Continue reading
Posted in Fun, Linux
Leave a comment
Added “ps” extras feature to tpe-lkm
Since I already had my hands in the tpe-lkm code yesterday, I decided to spend my lunch break coding a feature I’ve been meaning to add in for a while now. I added a new ps extras feature. Since it … Continue reading
Posted in Fun, Linux, Notices, Security
Leave a comment
tpe-lkm DoS condition fixed
I have committed a fix to the tpe-lkm project that fixes a DoS condition I previously noted. It also introduces a new sysctl entry, log_max, as to prevent logs from getting filled up horizontally. I set the default to 50, … Continue reading
Posted in Linux, Security
Leave a comment