On Fri, Aug 17, 2018 at 01:22:31PM -0500, Eric W. Biederman wrote: > Dmitry Vyukov <dvyukov@xxxxxxxxxx> writes: > > > On Wed, Aug 15, 2018 at 9:01 PM, Eric W. Biederman > > <ebiederm@xxxxxxxxxxxx> wrote: > >> Dmitry Vyukov <dvyukov@xxxxxxxxxx> writes: > >> > >>> On Tue, Aug 14, 2018 at 12:11 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > >>>> On Mon, Aug 13, 2018 at 06:33:02AM -0700, syzbot wrote: > >>>>> syzbot has found a reproducer for the following crash on: > >>>>> > >>>>> HEAD commit: 5ed5da74de9e Add linux-next specific files for 20180813 > >>>>> git tree: linux-next > >>>> > >>>> I fetched linux-next but don't have 5ed5da74de9e. > >>> > >>> Hi Bruce, > >>> > >>> +Stephen for the disappeared linux-next commit. > >>> > >>> On the dashboard link you can see that it also happened on a more > >>> recent commit 4e8b38549b50459a22573d756dd1f4e1963c2a8d that I do see > >>> now in linux-next. > >>> > >>>> I'm also not sure why I'm on the cc for this. > >>> > >>> You've been pointed to by "./scripts/get_maintainer.pl -f fs/fcntl.c" > >>> as maintainer of the file, which is the file where the crash happened. > >> > >> You need to use your reproducer to bisect and find the commit that > >> caused this. Otherwise you will continue to confuse people. > >> > >> get_maintainer.pl is not a good target for automated reporting > >> especially against linux-next. > > > > Hi Eric, > > > > We will do bisection. > > But I afraid it will not give perfect attribution for a number of reasons: > > - broken build/boot which happens sometimes for prolonged periods and > > prohibits bisection > > - elusive races that can't be reproduced reliably and thus bisection > > can give wrong results > > - bugs introduced too long ago (e.g. author email is not even valid today) > > - reproducers triggering more than 1 bug, so base bisection commit > > can actually be for another bug, or bisection can switch from one bug > > to another > > - last but not least, bugs without reproducers > > Bisection will add useful information to the bug report, but it will > > not necessary make attribution better than it is now. > > > > Do you have more examples where bugs were misreported? From what I see > > current attrition works well. There are episodic fallouts, but well, > > nothing is perfect in this world. Humans don't bisect frequently and > > misreport sometimes. I think we just need to re-route bugs in such > > cases. > > I have yet to see syzbot make a good report. Especially against > linux-next. It did result in a fix (thanks!): https://lkml.org/lkml/2018/8/16/47 So I'd call that a better-than-nothing report if not a great report? There's some value just in timeliness; it's a lot easier for me to fix a bug that I introduced in the last few days, with the change still fresh in my mind.... --b.
