Red Hat Bugzilla – Bug 280861
Kernel panic after issuing a pair of commands (needs root user)
Last modified: 2007-11-30 17:07:47 EST
Description of problem:
First of all, I'm not using RHEL5 but CentOS5. People under the IRC #centos
channel suggested me to file a bug directly to RedHat due the severity of the
problem. So that's why I'm here.
The problem was encountered by a mistake trying to link a loop device to a
file using the mount command instead losetup, and then after the expected
error message from the mount command, I changed mount by losetup and just
after press Enter the system freezes.
NOTE: maybe the mount and losetup steps need to be completed two times to
generate the kernel panic.
I've reproduced the problem under different machines using the same up to date
CentOS 5 system with the same results.
Version-Release number of selected component (if applicable):
mount --version says:
mount (util-linux 2.13-pre7)
Always, maybe need two passes instead only one in some machines.
Steps to Reproduce:
The following are the steps to reproduce the problem:
(other steps may reproduce the problem too, but to make sure use theses ones)
1) Download the floppy boot image from here:
2) Convert it to a cdrom boot image using the following command:
mkisofs -R -b boot.img boot.img > boot-cdrom.iso
3) mount /dev/loop0 boot-cdrom.iso
(it will display a normal error message here)
4) losetup /dev/loop0 boot-cdrom.iso
It must panic here, otherwise do a "losetup -d /dev/loop0" and go to step 3.
Kernel panic - not syncing: Fatal exception
The command should work finely.
I could reproduce the crash with 2.6.18-8.1.8.el5, but not with a current
development build. The issue looks similar to bug 236880. Possibly fixed already.
Jordi, can you test a recent kernel development build from
I have just upgraded my CentOS 5 to the very last kernel 2.6.18-8.1.10.el5 and
the kernel panic still persist.
Remember that it may need two passes before see the panic (steps 3 and 4)
2.6.18-8.1.10.el5 does not have the fix for bug 236880. Can you please test a
newer kernel from http://people.redhat.com/dzickus/el5/ ? E.g. version 49.el5.
Ok, I have tested it with the kernel 2.6.18-49.el5 and it works finely. As you
said the problem was probably fixed.
I tried a lot of passes even I've executed a shell-script with the steps 3 and 4
inside a while [ 1 ] loop during several minutes, and the panic was not seen.
I think you can close this issue.
*** This bug has been marked as a duplicate of 236880 ***