From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: syzbot <syzbot+ea7d9cb314b4ab49a18a@syzkaller.appspotmail.com>,
David Miller <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
LKML <linux-kernel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: INFO: rcu detected stall in ndisc_alloc_skb
Date: Sat, 5 Jan 2019 19:49:11 +0900 [thread overview]
Message-ID: <8cdbcb63-d2f7-cace-0eda-d73255fd47e7@i-love.sakura.ne.jp> (raw)
In-Reply-To: <eeb95c52-5bf8-d3ce-d32b-269aa86bcd93@i-love.sakura.ne.jp>
On 2019/01/03 2:06, Tetsuo Handa wrote:
> On 2018/12/31 17:24, Dmitry Vyukov wrote:
>>>> Since this involves OOMs and looks like a one-off induced memory corruption:
>>>>
>>>> #syz dup: kernel panic: corrupted stack end in wb_workfn
>>>>
>>>
>>> Why?
>>>
>>> RCU stall in this case is likely to be latency caused by flooding of printk().
>>
>> Just a hypothesis. OOMs lead to arbitrary memory corruptions, so can
>> cause stalls as well. But can be what you said too. I just thought
>> that cleaner dashboard is more useful than a large assorted pile of
>> crashes. If you think it's actionable in some way, feel free to undup.
>>
>
> We don't know why bpf tree is hitting this problem.
> Let's continue monitoring this problem.
>
> #syz undup
>
A report at 2019/01/05 10:08 from "no output from test machine (2)"
( https://syzkaller.appspot.com/text?tag=CrashLog&x=1700726f400000 )
says that there are flood of memory allocation failure messages.
Since continuous memory allocation failure messages itself is not
recognized as a crash, we might be misunderstanding that this problem
is not occurring recently. It will be nice if we can run testcases
which are executed on bpf-next tree.
next prev parent reply other threads:[~2019-01-05 10:50 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-31 7:42 INFO: rcu detected stall in ndisc_alloc_skb syzbot
2018-12-31 7:49 ` Dmitry Vyukov
2018-12-31 8:17 ` Tetsuo Handa
2018-12-31 8:24 ` Dmitry Vyukov
2019-01-02 17:06 ` Tetsuo Handa
2019-01-05 10:49 ` Tetsuo Handa [this message]
2019-01-06 13:24 ` Dmitry Vyukov
2019-01-06 13:47 ` Tetsuo Handa
2019-01-07 11:12 ` Dmitry Vyukov
2019-01-18 5:20 ` Tetsuo Handa
2019-01-19 12:16 ` Dmitry Vyukov
2019-01-19 13:10 ` Tetsuo Handa
2019-01-20 13:30 ` Dmitry Vyukov
2019-01-20 14:24 ` Tetsuo Handa
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