Crashes in packages from PPAs are often invalid

[dobey]

When crashes are uploaded to errors.u.c, it seems that PPA sources are not used when retracing, and this results in stack traces that may appear valid, but which point to parts of code which may not be where the crash actually occurred, as the package came from a PPA, such as one of the landing silo PPAs. This makes it very difficult to debug some especially difficult crashes, while testing silos.

[dobey (dobey)]

A possible two-step solution to this problem could be:

1) Fix apport to include a list of apt sources in use (without any credentials as included in sources.list files) in the crash report, so that the server may determine if necessary to pull in dbgsym packages from those PPAs to get a proper retrace.

2) Fix the retracer to add the necessary sources entries to grab additional dbgsym packages from the PPAs, or to flag the error as not retraceable, due to required packages not being installable, as they are from private PPAs, external archives, manually installed, etc…

This could be done initially as a whitelisted set of PPAs to allow installing additional packages from, on the server, so that packages from landing silo PPAs may be used in retracing. I think it would be good to open this up to all public PPAs in the future as well, as long as any security and other concerns are taken care of, and if we could open up viewing of crashes to others via SSO, so that they can see crash reports for packages in PPAs they own (if that is at all viable).

[Brian Murray (brian-murray)]

10:41 < slangasek> dobey, bdmurray: the concern is whether a
                   hostile ppa could feed the retracers bad symbols
                   that break gdb and compromise the retracer env.
                   I do not assume that gdb has been well-hardened
                   against hostile input
10:43 < dobey> slangasek: right, but i presume we can assume the
               landing silo PPAs to be safe in that regard, since
               we do binary copies from them to archive when landing
10:44 < slangasek> dobey: yes, we can rely on that being safe