From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
syzbot
<bot+73a7bec1bc0f4fc0512a246334081f8c671762a8@syzkaller.appspotmail.com>,
Christoph Lameter <cl@linux.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
syzkaller-bugs@googlegroups.com,
Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: WARNING: suspicious RCU usage (3)
Date: Wed, 29 Nov 2017 12:50:59 -0800 [thread overview]
Message-ID: <20171129205059.GI3624@linux.vnet.ibm.com> (raw)
In-Reply-To: <CACT4Y+YLi5qw1z4t4greG05n_2NL3mpXjhT7F-Kh-YeN4HWC3g@mail.gmail.com>
On Wed, Nov 29, 2017 at 07:25:32AM +0100, Dmitry Vyukov wrote:
> On Tue, Nov 28, 2017 at 11:30 PM, Paul E. McKenney
> <paulmck@linux.vnet.ibm.com> wrote:
> > On Tue, Nov 28, 2017 at 01:30:26PM -0800, Andrew Morton wrote:
> >> On Tue, 28 Nov 2017 12:45:01 -0800 syzbot <bot+73a7bec1bc0f4fc0512a246334081f8c671762a8@syzkaller.appspotmail.com> wrote:
> >>
> >> > Hello,
> >> >
> >> > syzkaller hit the following crash on
> >> > b0a84f19a5161418d4360cd57603e94ed489915e
> >> > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> >> > compiler: gcc (GCC) 7.1.1 20170620
> >> > .config is attached
> >> > Raw console output is attached.
> >> >
> >> > Unfortunately, I don't have any reproducer for this bug yet.
> >> >
> >> > WARNING: suspicious RCU usage
> >>
> >> There's a bunch of other info which lockdep_rcu_suspicious() should
> >> have printed out, but this trace doesn't have any of it. I wonder why.
> >
> > Yes, there should be more info printed, no idea why it would go missing.
>
> I think that's because while reporting "suspicious RCU usage" kernel hit:
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000074
>
> and the rest of the report is actually about the NULL deref.
>
> syzkaller hits too many crashes at the same time. And it's a problem
> for us. We get reports with corrupted/intermixed titles,
> corrupted/intermixed bodies, reports with same titles but about
> different bugs, etc.
Got it, thank you!
Thanx, Paul
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next prev parent reply other threads:[~2017-11-29 20:51 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-28 20:45 WARNING: suspicious RCU usage (3) syzbot
2017-11-28 21:30 ` Andrew Morton
2017-11-28 22:30 ` Paul E. McKenney
2017-11-29 6:25 ` Dmitry Vyukov
2017-11-29 20:50 ` Paul E. McKenney [this message]
2017-11-29 5:06 ` Eric Biggers
2017-11-30 0:47 ` Eric Biggers
2017-11-30 8:04 ` Dmitry Vyukov
2017-12-01 8:28 ` Dmitry Vyukov
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