LinuxSecurity.com
Share your story
The central voice for Linux and Open Source security news
Home News Topics Advisories HOWTOs Features Newsletters About Register

Welcome!
Sign up!
EnGarde Community
Login
Polls
What is the most important Linux security technology?
 
Advisories
Community
Linux Events
Linux User Groups
Link to Us
Security Center
Book Reviews
Security Dictionary
Security Tips
SELinux
White Papers
Featured Blogs
All About Linux
DanWalsh LiveJournal
Securitydistro
Latest Newsletters
Linux Security Week: October 20th, 2014
Linux Advisory Watch: October 17th, 2014
Subscribe
LinuxSecurity Newsletters
E-mail:
Choose Lists:
About our Newsletters
RSS Feeds
Get the LinuxSecurity news you want faster with RSS
Powered By

  
System V IPC

3.3. System V IPC

Many Unix-like systems, including Linux and System V systems, support System V interprocess communication (IPC) objects. Indeed System V IPC is required by the Open Group's Single UNIX Specification, Version 2 [Open Group 1997]. System V IPC objects can be one of three kinds: System V message queues, semaphore sets, and shared memory segments. Each such object has the following attributes:

  • read and write permissions for each of creator, creator group, and others.

  • creator UID and GID - UID and GID of the creator of the object.

  • owning UID and GID - UID and GID of the owner of the object (initially equal to the creator UID).

When accessing such objects, the rules are as follows:

  • if the process has root privileges, the access is granted.

  • if the process' EUID is the owner or creator UID of the object, then the appropriate creator permission bit is checked to see if access is granted.

  • if the process' EGID is the owner or creator GID of the object, or one of the process' groups is the owning or creating GID of the object, then the appropriate creator group permission bit is checked for access.

  • otherwise, the appropriate ``other'' permission bit is checked for access.

Note that root, or a process with the EUID of either the owner or creator, can set the owning UID and owning GID and/or remove the object. More information is available in ipc(5).

    
Partner

 

Latest Features
Peter Smith Releases Linux Network Security Online
Securing a Linux Web Server
Password guessing with Medusa 2.0
Password guessing as an attack vector
Squid and Digest Authentication
Squid and Basic Authentication
Demystifying the Chinese Hacking Industry: Earning 6 Million a Night
Free Online security course (LearnSIA) - A Call for Help
What You Need to Know About Linux Rootkits
Review: A Practical Guide to Fedora and Red Hat Enterprise Linux - Fifth Edition
Yesterday's Edition
Hacker Halted 2014: Johnny Long Calls for Hackers for Charity Volunteers
RIPS – Static Source Code Analysis For PHP Vulnerabilities
Finding a Video Poker Bug Made These Guys Rich—Then Vegas Made Them Pay
Partner Sponsor

Community | HOWTOs | Blogs | Features | Book Reviews | Networking
 Security Projects |  Latest News |  Newsletters |  SELinux |  Privacy |  Home
 Hardening |   About Us |   Advertise |   Legal Notice |   RSS |   Guardian Digital
(c)Copyright 2014 Guardian Digital, Inc. All rights reserved.