Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Fork bomb

  1. #1
    Join Date
    Jul 2011
    Beans
    24

    Fork bomb

    I am new to learn about fork bomb. I saw in a website that limiting the number of process we can prevent fork bomb. What does it mean?

  2. #2
    Join Date
    Feb 2010
    Location
    White Plume Mountain
    Beans
    8,223
    Distro
    Ubuntu 14.04 Trusty Tahr

    Re: Fork bomb

    I haven't heard of many home users being hit with a fork bomb style DoS attack.

    http://en.wikipedia.org/wiki/Fork_bomb
    Thank you for your contributions. "So long and thanks for the fish!"

  3. #3
    Join Date
    Jul 2011
    Beans
    24

    Re: Fork bomb

    In what way does fork bomb harm any system. Is it through the net we use or inbuilt in the system when we work on more applications?

  4. #4
    Join Date
    Feb 2010
    Location
    White Plume Mountain
    Beans
    8,223
    Distro
    Ubuntu 14.04 Trusty Tahr

    Re: Fork bomb

    The link I provided above explains Fork Bombs. If you are not running server applications and you are not forwarding ports at your router/firewall, then you have nothing to worry about. It is a Denial of Service(DoS) attack.
    Thank you for your contributions. "So long and thanks for the fish!"

  5. #5
    Join Date
    Dec 2007
    Location
    The last place I look
    Beans
    Hidden!
    Distro
    Ubuntu 10.04 Lucid Lynx

    Re: Fork bomb

    a fork bomb is a denial of service attack, that is caused by a malicious program that keeps running fork() on itself infinitely. fork() causes a new process to spawn (usually a clone of the process calling fork). Fork is particularly needed for server services that listen on one port, but that then run established connections from a different port.

    the system has a list of running processes (the process table), but that list can be filled up. when it is, no other processes can be started.


    the advice you are hearing, is telling you to make sure that you set a maximum number of processes that may run, which is less than the max number the system can support. that way your list of processes can never overflow.

    https://secure.wikimedia.org/wikiped...wiki/Fork_bomb
    Last edited by doas777; July 15th, 2011 at 07:24 PM.
    Things are rarely just crazy enough to work, but they're frequently just crazy enough to fail hilariously.

  6. #6
    Soul-Sing is offline Chocolate-Covered Ubuntu Beans
    Join Date
    Aug 2006
    Beans
    1,374
    Distro
    Ubuntu 13.04 Raring Ringtail

    Re: Fork bomb

    :http://ubuntuforums.org/announcement.php?f=48
    Forkbomb: Executes a huge number of processes until system freezes, forcing you to do a hard reset which may cause corruption, data damage, or other awful fates.
    In Bourne-ish shells, like Bash: (This thing looks really intriguing and curiousity provokes)
    warning malicious commands:
    We've recently had an increase in the number of dangerous commands being posted on the forums. Don't pretend you don't know what I mean -- commands that cause massive damage or disruption to the user's computer.

  7. #7
    Join Date
    Jul 2011
    Beans
    24

    Re: Fork bomb

    Quote Originally Posted by leoquant View Post
    If I am running too many process and if it results in a fork bomb problem I must restart or reboot my system to stop it. Why not I use kill or killall to stop that process. Will it completely kill the fork bomb? What does rebooting my system do?

  8. #8
    Join Date
    Feb 2010
    Location
    White Plume Mountain
    Beans
    8,223
    Distro
    Ubuntu 14.04 Trusty Tahr

    Re: Fork bomb

    Quote Originally Posted by kirthi View Post
    If I am running too many process and if it results in a fork bomb problem I must restart or reboot my system to stop it. Why not I use kill or killall to stop that process. Will it completely kill the fork bomb? What does rebooting my system do?
    You can't run kill or killall if your system is already running its maximum number of processes.
    Thank you for your contributions. "So long and thanks for the fish!"

  9. #9
    Join Date
    Dec 2007
    Location
    The last place I look
    Beans
    Hidden!
    Distro
    Ubuntu 10.04 Lucid Lynx

    Re: Fork bomb

    Quote Originally Posted by kirthi View Post
    If I am running too many process and if it results in a fork bomb problem I must restart or reboot my system to stop it. Why not I use kill or killall to stop that process. Will it completely kill the fork bomb? What does rebooting my system do?
    well the problem is that the DOS is accomplished by filling up your process table to the extent that you cannot spawn new processes, including the instance of killall.
    so if you can get it to run, killall should work, but if the fork processes are not consuming resources beyond a entry in the process tab, then you would probably not notice all the forked processes until you have reach the max and are effectively locked out.

    your process table is in ram, and gets recreated upon each boot. thats why rebooting fixes the problem.
    Things are rarely just crazy enough to work, but they're frequently just crazy enough to fail hilariously.

  10. #10
    Join Date
    Jul 2011
    Beans
    24

    Re: Fork bomb

    Quote Originally Posted by uRock View Post
    You can't run kill or killall if your system is already running its maximum number of processes.
    It have been said in a website that using kill or killall we can terminate the bomb's process. And exec() can be used which replaces shell process with specified program.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •