Pen Testing
Stale NFS File Handle Locks In BackTrack 4 Beta
Operating System:
BackTrack 4 Beta (This issue seems to be a regular problem on Debian based systems including Ubuntu)
Symptoms:
Grey screen with a black X for the mouse cursor
During boot process or from dmesg: Activating swapfile swap [fail]
Cannot delete folders and files related to X11 in /mnt/sdb2/changes/tmp (BackTrack) or /tmp (Debian/Ubuntu) because of a "Stale NFS file handle.":
Warning: Be sure to make a backup of your important files prior to running any of these commands.
To resolve this issue in BackTrack4 Beta (or Debian based system) without reformatting and restoring your original BackTrack4 Beta boot partition:
Identify your persistent partition:
Attempt to unmount your persistent partition (mine was /dev/sdb2):
If BackTrack reports that it is unable to unmount the folder, because various processes are in use -- find processes that are being used by the partition:
Attempt to gracefully kill processes found from the fuser command:
If graceful kill didn't work:
You should now be able to unmount the partition:
If you formatted the partition as ext3, run the e2fsck.ext3 command to check and repair your file system:
At this point, you will need to keep pressing y, and allow e2fsck to repair and remove files as needed.
OR If you don't care to read what is being repaired and removed:
Restart your system when e2fsck is done, and you should be back in business.
BackTrack 4 Beta Networking
After successfully installing and booting into BackTrack 4 Beta, you can load up other packages such as Nessus -- however, BackTrack 4 Beta comes configured with just the local loopback.
Running "dhcpcd eth0" won't work -- dhcpcd isn't installed, and you can't install online packages until networking is configured correctly. Also, KNetworkManager refused to startup in KDE on my test system.
The easiest way for me to get online was to edit /etc/network/interfaces and set a static ip:
Change the bottom line -- iface eth0 inet dhcp to:
Update DNS name servers:
Restart networking:
Verify that eth0's settings are correct:
Download to your heart's content.
USB Drive Setup For BackTrack 4 Beta
If you already have a formatted USB drive, that loads BackTrack 3 Final or 4 Beta, you can skip this article.
If your drive isn't formatted correctly:
Follow Sanjat Kabi's "Install Linux to a USB flash drive" steps 4-11.
Changes I used for BackTrack 4 Beta DVD:
Replace +750M with +1000M.
type c to select W95 FAT32 (LBA) where Sanjat says to type 6 for FAT16
After running UNetbootin, you should have a working boot of Backtrack 4 Beta. However, if you see the message "Boot Error" during startup:
1. Plug your USB drive into a MS Windows system.
2. Right-click the Windows Start button and select "Explore."
3. Go to your USB drive and right-click the drive letter, then select "Format." (Be sure you are on the correct drive and not your C: windows drive.) Select FAT32 and do not check "Quick Format."
4. After formatting is done, run UNetbootin from Windows.
5. Click on the "Diskimage" option.
5. Select your BackTrack 4 Beta DVD iso (I'm assuming you have already downloaded and verified the md5sum of the iso).
6. After UNetbootin installs and configures BackTrack 4, just restart and hopefully you don't get that "Boot Error" message.
Depending on your USB drive, you may or may not have to do the above steps. I had to do these steps for a Super Talent 4GB USB 2.0 drive.
NOTE: FAT16 and FAT32 both worked for me.
BackTrack 4 Beta: Now Uses Debian Packages and Ubuntu Repos
The BackTrack team over at remote-exploit.org has released BackTrack 4 Beta with new features and considerable changes.
Download a copy of BackTrack 4 Beta from http://www.remote-exploit.org/backtrack_download.html .
Softpedia has highlights of BackTrack 4 Beta, if you care to read about some of the changes.
If you want to load BackTrack 4 Beta to a USB drive with persistent changes, Infosec Ramblings has a well-written guide. Unetbootin makes transfering .iso images so easy - compared to the runaround of the past to get BackTrack installed to a USB drive.
