From: Dmitry Vyukov <dvyukov@google.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: syzbot <syzbot+660883c56e2fa65d4497@syzkaller.appspotmail.com>,
David Miller <davem@davemloft.net>,
Johan Hedberg <johan.hedberg@gmail.com>,
linux-bluetooth <linux-bluetooth@vger.kernel.org>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
Marcel Holtmann <marcel@holtmann.org>,
Michal Marek <mmarek@suse.com>, Netdev <netdev@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: KASAN: slab-out-of-bounds Read in bacpy
Date: Sun, 17 Mar 2019 18:11:49 +0100 [thread overview]
Message-ID: <CACT4Y+YOWaU8s90joeGB4G1oc-GxrQSDnjpuFOuE4eJd5FHK3g@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wjUrznUSUKN1AXQA9kCStQ3MHFY95ZmeTZ5zYDcvMhBiQ@mail.gmail.com>
On Sun, Mar 17, 2019 at 5:35 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> On Sun, Mar 17, 2019 at 3:43 AM syzbot
> <syzbot+660883c56e2fa65d4497@syzkaller.appspotmail.com> wrote:
> >
> > syzbot has bisected this bug to:
> >
> > commit c470abd4fde40ea6a0846a2beab642a578c0b8cd
> > Author: Linus Torvalds <torvalds@linux-foundation.org>
> > Date: Sun Feb 19 22:34:00 2017 +0000
>
> Heh. Yeah, I doubt it.
>
> It would probably be good if syzbot did some confidence testing before
> bisecting.
>
> Don't get me wrong, "git bisect" is absolutely wonderful and has done
> a ton to help us fix bugs, but bisection has one major downside: if
> the bug you are bisecting isn't 100% repeatable, the bisection will go
> off into the random weeds and give completely nonsensical results.
> They won't even be *close*. What makes bisection so powerful is also
> what makes it then completely random if there's even *one* mistaken
> bisection point.
>
> So it would probably be good to test each bisection point at least
> twice, and if they don't agree, report it as being unbisectable rather
> than give a random "this is what introduced the problem".
>
> Hmm?
Hi Linus,
Please see https://github.com/google/syzkaller/blob/master/docs/syzbot.md#bisection
it should answer all of your questions. It does 2 and more.
And in this case it seems to be working as intended bisecting it to a
release tag.
next prev parent reply other threads:[~2019-03-17 17:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-07 13:31 KASAN: slab-out-of-bounds Read in bacpy syzbot
2019-03-17 10:43 ` syzbot
2019-03-17 16:35 ` Linus Torvalds
2019-03-17 17:11 ` Dmitry Vyukov [this message]
2019-03-17 19:24 ` Stefano Brivio
2019-03-18 13:00 ` Dmitry Vyukov
2019-03-17 20:41 ` Linus Torvalds
2019-03-19 13:27 ` Dmitry Vyukov
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