Filing Kernel Bug reports
The preferred method for reporting a bug against the Ubuntu kernel is done by running the following command from a terminal window (Applications->Accessories->Terminal). It will automatically file an Ubuntu kernel bug in Launchpad. More importantly, it will automatically gather and attach important system information to the bug report.
$ ubuntu-bug linux
The submitter should provide as much information as possible in the bug description:
- The majority of kernel bug are hardware specific so be sure to note what hardware/device is being used.
- Document any known steps to reproduce the bug.
- Also note whether the bug exists in previous kernel versions of Ubuntu or if it's a regression from previous kernel versions.
Finally, it's critical to also make sure to test the latest development Ubuntu kernel version as well as the latest upstream mainline kernel.
If there are any questions about what information to provide, please contact a developer in the #ubuntu-kernel channel on the FreeNode IRC server for help on how to file a bug.
Adding debug info to a bug report
If you didn't file your Ubuntu kernel bug using ubuntu-bug, please run the following which will automatically gather and attach the requested system information to the bug report:
$ apport-collect -p linux BUG#
As a last resort, at a minimum, your bug report should contain the output of the following commands:
$ uname -a > uname-a.log $ cat /proc/version_signature > version.log $ dmesg > dmesg.log $ sudo lspci -vvnn > lspci-vvnn.log
These four files should be attached separately to the bug report (not pasted into comments, tarred, or compressed). Please note that dmesg output should be captured as early as possible after bootup to avoid extraneous output.
Reporting Bugs Upstream
Depending on the phase of the Ubuntu release cycle, the Ubuntu kernel team will rebase the Ubuntu kernel with the upstream mainline kernel. Unfortunately, it is sometimes the case that bugs can still exist in the upstream mainline kernel. If you know your bug exists upstream, you should also report your bug upstream. It is often the case that once a bug is escalated upstream there is a quick resolution through the help and support of the mainline kernel community. For more on reporting a bug upstream, please see here.