In Unix, every process has a real user id (ruid), an effective user id (euid), and a saved user id (suid). Processes with an euid of 0 have special root privileges. a. If a process with user id n forks to create another process, what user id does the new process have? (Hint: it's the same answer for euid, ruid, and suid.) b. If a process with euid n makes a setuid system call, what possible euids can the process run with after the call, in each of the following situations: a. Before: euid = n> 0, saved user id suid=m and real user id ruid = m. After:? b. Before: n=0 After:? c. In qmail, most modules run under separate user ids. Similarly, each Android application runs in a separate process using a separate user id. From a security standpoint, what is the advantage of assigning separate uids instead of using the same uid for all? Explain. d. Why should the separate uids be non-zero?

Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
Problem 1PE
icon
Related questions
Question

Answer all parts otherwise I will down vote

Problem 6: Unix access control
In Unix, every process has a real user id (ruid), an effective user id (euid), and a saved user id
(suid). Processes with an euid of 0 have special root privileges.
a. If a process with user id n forks to create another process, what user id does the new
process have? (Hint: it's the same answer for euid, ruid, and suid.)
b. If a process with euid n makes a setuid system call, what possible euids can the
process run with after the call, in each of the following situations:
a. Before: euid = n > 0, saved user id suid=m and real user id ruid = m. After:?
b. Before: n=0 After:?
c. In qmail, most modules run under separate user ids. Similarly, each Android
application runs in a separate process using a separate user id. From a security
standpoint, what is the advantage of assigning separate uids instead of using the
same uid for all? Explain.
d. Why should the separate uids be non-zero?
Transcribed Image Text:Problem 6: Unix access control In Unix, every process has a real user id (ruid), an effective user id (euid), and a saved user id (suid). Processes with an euid of 0 have special root privileges. a. If a process with user id n forks to create another process, what user id does the new process have? (Hint: it's the same answer for euid, ruid, and suid.) b. If a process with euid n makes a setuid system call, what possible euids can the process run with after the call, in each of the following situations: a. Before: euid = n > 0, saved user id suid=m and real user id ruid = m. After:? b. Before: n=0 After:? c. In qmail, most modules run under separate user ids. Similarly, each Android application runs in a separate process using a separate user id. From a security standpoint, what is the advantage of assigning separate uids instead of using the same uid for all? Explain. d. Why should the separate uids be non-zero?
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps

Blurred answer
Knowledge Booster
Race Condition
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Database System Concepts
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
Starting Out with Python (4th Edition)
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
Digital Fundamentals (11th Edition)
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
C How to Program (8th Edition)
C How to Program (8th Edition)
Computer Science
ISBN:
9780133976892
Author:
Paul J. Deitel, Harvey Deitel
Publisher:
PEARSON
Database Systems: Design, Implementation, & Manag…
Database Systems: Design, Implementation, & Manag…
Computer Science
ISBN:
9781337627900
Author:
Carlos Coronel, Steven Morris
Publisher:
Cengage Learning
Programmable Logic Controllers
Programmable Logic Controllers
Computer Science
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education