Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <CACT4Y+ZuGaeyyVsCkqJRo4+0hoMP8Eq_JTuU0L-NFqTrQP_czA@mail.gmail.com>
 <36C7F018-510E-4555-BC6B-42DEB0468CBA@lca.pw>
In-Reply-To: <36C7F018-510E-4555-BC6B-42DEB0468CBA@lca.pw>
From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Thu, 23 Apr 2020 10:49:38 +0200
Message-ID: <CACT4Y+a4NvM3K4auifUHsVM8POTAyhyTCbs6SW6AY27cOsuSMw@mail.gmail.com>
Subject: Re: linux-next test error: WARNING: suspicious RCU usage in ipmr_device_event
To:     Qian Cai <cai@lca.pw>
Cc:     syzbot <syzbot+21f82f61c24a7295edf5@syzkaller.appspotmail.com>,
        Linux-Next Mailing List <linux-next@vger.kernel.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        David Miller <davem@davemloft.net>, kuba@kernel.org,
        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>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Apr 21, 2020 at 1:21 PM Qian Cai <cai@lca.pw> wrote:
> > On Apr 21, 2020, at 6:51 AM, Dmitry Vyukov <dvyukov@google.com> wrote:
> >
> > +linux-next, Stephen for a new linux-next breakage
>
> I don=E2=80=99t know why you keep sending the same thing over and over ag=
ain where I replied you just two days ago for the same thing.

Well, formally this bug was never mailed. The other one is about
"WARNING: suspicious RCU usage in ovs_ct_exit". It just happened that
this "WARNING: suspicious RCU usage in ipmr_device_event" was appended
to that one (because kernel somehow failed to respect panic_on_warn?).
But warnings except the first one are ignored, frequently they are
induced and it's not possible to track 2 different bugs at the same
time in a reasonable way anyway.

So effectively this is the first occurance of this bug (presumably the
fix for ovs_ct_exit has reached linux-next). First occurrence is
always mailed.

Now let's tell syzbot that this one is fixed as well:

#syz fix: ipmr: Fix RCU list debugging warning