This guide should help you narrow down the right package. For bug triaging help find someone in the Bug Squad or ask on their mailing list or in #ubuntu-bugs.
The bugsquad has regular meetings and can probably find you a mentor if you want to help (and join!). For reference here's the Bug Triaging Guide.
So, in the example you've supplied, the bug is filed against the kernel package for the Ubuntu operating system. You can tell this by looking at the package listed under the 'Affects' block. In this case, it is linux(ubuntu) so it is distro specific.
Depending on how it is filed, a bug may not get the attention it needs. If it was filed against the 'Linux' project, then it is important to note that this is used as an upstream bug tracker for bugs against related distributions.
If this bug was something that you wanted to be addressed by upstream Linux maintainers, then really the only thing you can do is file it on bugzilla.kernel.org. The site being the bugtracker that Linus and the maintainers use to address kernel issues.
In this case, the Kernel Defect Analyst(me :-) ) would triage your bug and bring it to the attention of the Kernel Release Manager. S/He would then determine whether it needed an Engineer's involvement (this is somewhat ambiguous as the KRM is an Engineer in his/her own right so it may be worked by them as well). At that time it will be acted upon.
It is important to note that not all bugs get actively worked. In the vast majority of cases bugs are left alone if there is work ongoing upstream. If you are aware of the bug upstream, then filing a bug against Ubuntu in launchpad is an important way for us to track the issues as they progress in the upstream kernel. This would be accomplished by adding that upstream watch I mentioned earlier.
Hope that helps you a bit. Let me know if you'd like some clarification of any of the above.
Best Answer
(Source: Bugs/Importance (Bug Squad Documentation))
The Ubuntu Bug Squad is one of the driving forces for Ubuntu Bugs, and maintains a documentation of this for the reference of every person.
For the sake of people who hate reading other sites, and for the few people who might be too lazy to click on the link at the beginning of this answer, I'll basically copy verbatim the Bug Squad Knowledge base information that is relevant to here:
(Note the below information may be out of date with the documentation on the wiki, you should refer to the wiki for the most up-to-date information.)
Ubuntu uses the following guidelines for assigning importance. The importance of the bug signifies the priority that it should be given by people fixing bugs.
Here are the meanings of the different importance values):
The Ubuntu Bug Control members have the access to set these importance statuses on bugs under the purview of Ubuntu (including packages, which
ubuntu-bug
will do), and can either set them themselves, or at the request of a member of the Bug Squad who is not a Bug Control member.Generally, when I handle bugs and decide an importance and whether its ready for triaging (unless its blatantly obvious), I follow the Triage Guide for deciding how to triage the bug (which sets the Status of a bug to "Triaged") and the guidelines I've posted (and linked to) above for deciding Importance. (I'm on the Bug Squad, and I am a member of Bug Control, if you're curious)