Re: KASAN: user-memory-access Read in ip6_hold_safe (3)

From: Dmitry Vyukov
Date: Mon Jun 03 2019 - 03:00:09 EST


On Sat, Jun 1, 2019 at 7:15 PM David Ahern <dsahern@xxxxxxxxx> wrote:
>
> On 6/1/19 12:05 AM, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: dfb569f2 net: ll_temac: Fix compile error
> > git tree: net-next
> syzbot team:
>
> Is there any way to know the history of syzbot runs to determine that
> crash X did not happen at commit Y but does happen at commit Z? That
> narrows the window when trying to find where a regression occurs.

Hi David,

All info is available on the dashboard:

> dashboard link: https://syzkaller.appspot.com/bug?extid=a5b6e01ec8116d046842

We don't keep any private info on top of that.

This crash happened 129 times in the past 9 days. This suggests this
is not a previous memory corruption, these usually happen at most few
times.
The first one was:

2019/05/24 15:33 net-next dfb569f2

Then it was joined by bpf-next:

ci-upstream-bpf-next-kasan-gce 2019/06/01 15:51 bpf-next 0462eaac

Since it happens a dozen of times per day, most likely it was
introduced into net-next around dfb569f2 (syzbot should do new builds
every ~12h, minus broken trees).