On Fri, Dec 06, 2019 at 12:10:41AM +1100, Daniel Axtens wrote: > Daniel Borkmann <daniel@xxxxxxxxxxxxx> writes: > > On Thu, Dec 05, 2019 at 03:35:21PM +1100, Daniel Axtens wrote: > >> >> HEAD commit: 1ab75b2e Add linux-next specific files for 20191203 > >> >> git tree: linux-next > >> >> console output: https://syzkaller.appspot.com/x/log.txt?x=10edf2eae00000 > >> >> kernel config: https://syzkaller.appspot.com/x/.config?x=de1505c727f0ec20 > >> >> dashboard link: https://syzkaller.appspot.com/bug?extid=82e323920b78d54aaed5 > >> >> compiler: gcc (GCC) 9.0.0 20181231 (experimental) > >> >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=156ef061e00000 > >> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11641edae00000 > >> >> > >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: > >> >> Reported-by: syzbot+82e323920b78d54aaed5@xxxxxxxxxxxxxxxxxxxxxxxxx > >> > > >> > +Daniel, is it the same as: > >> > https://syzkaller.appspot.com/bug?id=f6450554481c55c131cc23d581fbd8ea42e63e18 > >> > If so, is it possible to make KASAN detect this consistently with the > >> > same crash type so that syzbot does not report duplicates? > >> > >> It looks like both of these occur immediately after failure injection. I > >> think my assumption that I could ignore the chance of failures in the > >> per-cpu allocation path will have to be revisited. That's annoying. > >> > >> I'll try to spin something today but Andrey feel free to pip me at the > >> post again :) > >> > >> I'm not 100% confident to call them dups just yet, but I'm about 80% > >> confident that they are. > > > > Ok. Double checked BPF side yesterday night, but looks sane to me and the > > fault also hints into pcpu_alloc() rather than BPF code. Daniel, from your > > above reply, I read that you are aware of how the bisected commit would > > have caused the fault? > > Yes, this one is on me - I did not take into account the brutal > efficiency of the fault injector when implementing my KASAN support for > vmalloc areas. I have a fix, I'm just doing final tests now. Perfect, thanks a lot!
