Re: KASAN: slab-out-of-bounds Read in fbcon_get_font

From: Paolo Bonzini
Date: Thu Dec 05 2019 - 06:29:31 EST


On 05/12/19 12:27, Dmitry Vyukov wrote:
> Oh, you mean the final bisection crash. Indeed it contains a kvm frame
> and it turns out to be a bug in syzkaller code that indeed
> misattributed it to kvm instead of netfilter.
> Should be fixed now, you may read the commit message for details:
> https://github.com/google/syzkaller/commit/4fb74474cf0af2126be3a8989d770c3947ae9478
>
> Overall this "making sense out of kernel output" task is the ultimate
> insanity, you may skim through this file to get a taste of amount of
> hardcoding and special corner cases that need to be handled:
> https://github.com/google/syzkaller/blob/master/pkg/report/linux.go
> And this is never done, such "exception from exception corner case"
> things pop up every week. There is always something to shuffle and
> tune. It only keeps functioning due to 500+ test cases for all
> possible insane kernel outputs:
> https://github.com/google/syzkaller/tree/master/pkg/report/testdata/linux/report
> https://github.com/google/syzkaller/tree/master/pkg/report/testdata/linux/guilty
>
> So thanks for persisting and questioning! We are getting better with
> each new test.

Thanks to you! I "complain" because I know you're so responsive. :)

Paolo