From: Dmitry Vyukov <dvyukov@google.com>
To: Qian Cai <cai@lca.pw>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Xu <peterx@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, Jens Axboe <axboe@kernel.dk>,
Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
syzkaller <syzkaller@googlegroups.com>,
Dan Rue <dan.rue@linaro.org>
Subject: Re: [PATCH 0/2] mm: Two small fixes for recent syzbot reports
Date: Tue, 14 Apr 2020 14:05:21 +0200 [thread overview]
Message-ID: <CACT4Y+YE6N8MUL-hVps6+BxVoQ0Xi_4AS26j8e+tv=_L2vKuYA@mail.gmail.com> (raw)
In-Reply-To: <04E78431-7B62-4FA1-8B1D-51DF7648D9C5@lca.pw>
On Tue, Apr 14, 2020 at 1:59 PM Qian Cai <cai@lca.pw> wrote:
> > On Apr 14, 2020, at 7:13 AM, Dmitry Vyukov <dvyukov@google.com> wrote:
> >
> > How do these use-after-free's and locking bugs get past the
> > unit-testing systems (which syzbot is not) and remain unnoticed for so
> > long?...
> > syzbot uses the dumbest VMs (GCE), so everything it triggers during
> > boot should be triggerable pretty much everywhere.
>
> There are many reasons that any early testing would not be able to catch ALL the syzbot blockers.
>
> The Kconfigs are different. For example, I don’t have openvswitch enabled, so would miss that ovs rcu-list lockdep warning. Same for that use-after-free in net/bluetooth and a warning in sound subsystem.
>
> But, notifying Linux-next ML is a good start, so at least we could ask Paul or Steve to pull out the commit which enabling rcu-list debugging by default with PROVE_RCU.
>
> I learned through that restricted kconfig to some degree of minimal could save a lot of troubles late on especially those options that I have no way to exercise like net/bluetooth and sound currently. It is going to be extra works though because those default options in Linux-next or even defconfigs are not always pleasant and would want to enable something I don’t need if not given human intervention.
We only try to enable what we can reach. There is significant reach
for sound and net/bluetooth even without any hardware. So I would
assume generic testing systems like KernelCI, LKFT, CKI should enable
these as well. Hopefully we don't have all of the sound and
net/bluetooth completely untested in linux-next.
next prev parent reply other threads:[~2020-04-14 12:05 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-08 1:40 [PATCH 0/2] mm: Two small fixes for recent syzbot reports Peter Xu
2020-04-08 1:40 ` [PATCH 1/2] mm/mempolicy: Allow lookup_node() to handle fatal signal Peter Xu
2020-04-08 10:21 ` Michal Hocko
2020-04-08 14:20 ` Peter Xu
2020-04-08 14:30 ` Michal Hocko
2020-04-08 15:24 ` Peter Xu
2020-04-08 15:26 ` Michal Hocko
2020-04-09 7:02 ` Michal Hocko
2020-04-09 12:52 ` Peter Xu
2020-04-09 13:00 ` Peter Xu
2020-04-09 13:53 ` Michal Hocko
2020-04-09 16:42 ` Linus Torvalds
2020-04-14 11:04 ` Michal Hocko
2020-04-14 13:49 ` Peter Xu
2020-04-14 14:18 ` Michal Hocko
2020-04-20 12:47 ` Michal Hocko
2020-04-20 17:31 ` Linus Torvalds
2020-04-21 7:09 ` Michal Hocko
2020-04-08 1:40 ` [PATCH 2/2] mm/gup: Mark lock taken only after a successful retake Peter Xu
2020-04-09 0:47 ` [PATCH 0/2] mm: Two small fixes for recent syzbot reports Andrew Morton
2020-04-09 11:49 ` Matthew Wilcox
2020-04-09 13:00 ` Dmitry Vyukov
2020-04-09 18:16 ` Andrew Morton
2020-04-09 18:53 ` Linus Torvalds
2020-04-09 19:12 ` Andrew Morton
2020-04-09 19:46 ` Linus Torvalds
2020-04-09 19:56 ` Matthew Wilcox
2020-04-09 19:58 ` Linus Torvalds
2020-04-09 20:27 ` Eric Biggers
2020-04-09 20:34 ` Linus Torvalds
2020-04-09 23:34 ` Stephen Rothwell
2020-04-10 1:11 ` Theodore Y. Ts'o
2020-04-09 12:55 ` Dmitry Vyukov
2020-04-09 16:32 ` Linus Torvalds
2020-04-09 16:58 ` Qian Cai
2020-04-09 17:05 ` Linus Torvalds
2020-04-09 17:58 ` Qian Cai
2020-04-09 18:06 ` Linus Torvalds
2020-04-09 21:14 ` Qian Cai
2020-04-10 13:12 ` Tetsuo Handa
2020-04-10 14:26 ` Qian Cai
2020-04-10 17:26 ` Andrew Morton
2020-04-10 19:46 ` Qian Cai
2020-04-09 23:29 ` Stephen Rothwell
2020-04-13 22:06 ` Qian Cai
2020-04-13 23:05 ` Jens Axboe
2020-04-14 11:12 ` Dmitry Vyukov
2020-04-14 11:59 ` Qian Cai
2020-04-14 12:05 ` Dmitry Vyukov [this message]
2020-04-14 19:28 ` Dan Rue
2020-04-15 11:09 ` Dmitry Vyukov
2020-04-15 16:23 ` Dan Rue
2020-04-16 0:34 ` Stephen Rothwell
2020-05-11 15:29 ` Dmitry Vyukov
2020-04-14 4:07 ` Hillf Danton
2020-04-14 4:31 ` Jens Axboe
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