From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Xin Long <lucien.xin@gmail.com>,
Vlad Yasevich <vyasevich@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
"David S. Miller" <davem@davemloft.net>,
linux-sctp@vger.kernel.org, netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Dmitry Vyukov <dvyukov@google.com>,
Eric Dumazet <edumazet@google.com>,
Kostya Serebryany <kcc@google.com>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: net/sctp: list double add warning in sctp_endpoint_add_asoc
Date: Wed, 5 Apr 2017 11:22:05 -0300 [thread overview]
Message-ID: <20170405142205.GD911@localhost.localdomain> (raw)
In-Reply-To: <CAAeHK+xQxcQB92NK5-xBtd2rWQRGWPv29G5jePva2c2sTg248Q@mail.gmail.com>
On Wed, Apr 05, 2017 at 04:02:44PM +0200, Andrey Konovalov wrote:
> On Tue, Apr 4, 2017 at 11:14 PM, Marcelo Ricardo Leitner
> <marcelo.leitner@gmail.com> wrote:
> > On Wed, Apr 05, 2017 at 01:29:19AM +0800, Xin Long wrote:
> >> On Tue, Apr 4, 2017 at 9:28 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
> >> > Hi,
> >> >
> >> > I've got the following error report while fuzzing the kernel with syzkaller.
> >> >
> >> > On commit a71c9a1c779f2499fb2afc0553e543f18aff6edf (4.11-rc5).
> >> >
> >> > A reproducer and .config are attached.
> >> The script is pretty hard to reproduce the issue in my env.
> >
> > I didn't try running it but I also found the reproducer very complicated
> > to follow. Do you have any plans on having some PoC optimizer, so we can
> > have a more readable code?
> > strace is handy for filtering the noise, yes, but sometimes it doesn't
> > cut it.
>
> We do have some plans (like to remote all those unnecessary helper
> functions), but it's probably not going to become much better.
>
> You mostly only need to look at the thr() function to understand
> what's going on.
Okay.
>
> What I sometimes do is run each of the switch cases under strace
> separately to understand what each of them do.
>
> I've also attached a program in syzkaller format.
> You can take a look at it, if you find it useful, I can start
> attaching them for subsequent reports.
Comparing it to thr() they look very close, at least for this one.
But when you cannot extract a reproducer, it will certainly help.
Thanks,
Marcelo
WARNING: multiple messages have this Message-ID (diff)
From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Xin Long <lucien.xin@gmail.com>,
Vlad Yasevich <vyasevich@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
"David S. Miller" <davem@davemloft.net>,
linux-sctp@vger.kernel.org, netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Dmitry Vyukov <dvyukov@google.com>,
Eric Dumazet <edumazet@google.com>,
Kostya Serebryany <kcc@google.com>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: net/sctp: list double add warning in sctp_endpoint_add_asoc
Date: Wed, 05 Apr 2017 14:22:05 +0000 [thread overview]
Message-ID: <20170405142205.GD911@localhost.localdomain> (raw)
In-Reply-To: <CAAeHK+xQxcQB92NK5-xBtd2rWQRGWPv29G5jePva2c2sTg248Q@mail.gmail.com>
On Wed, Apr 05, 2017 at 04:02:44PM +0200, Andrey Konovalov wrote:
> On Tue, Apr 4, 2017 at 11:14 PM, Marcelo Ricardo Leitner
> <marcelo.leitner@gmail.com> wrote:
> > On Wed, Apr 05, 2017 at 01:29:19AM +0800, Xin Long wrote:
> >> On Tue, Apr 4, 2017 at 9:28 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
> >> > Hi,
> >> >
> >> > I've got the following error report while fuzzing the kernel with syzkaller.
> >> >
> >> > On commit a71c9a1c779f2499fb2afc0553e543f18aff6edf (4.11-rc5).
> >> >
> >> > A reproducer and .config are attached.
> >> The script is pretty hard to reproduce the issue in my env.
> >
> > I didn't try running it but I also found the reproducer very complicated
> > to follow. Do you have any plans on having some PoC optimizer, so we can
> > have a more readable code?
> > strace is handy for filtering the noise, yes, but sometimes it doesn't
> > cut it.
>
> We do have some plans (like to remote all those unnecessary helper
> functions), but it's probably not going to become much better.
>
> You mostly only need to look at the thr() function to understand
> what's going on.
Okay.
>
> What I sometimes do is run each of the switch cases under strace
> separately to understand what each of them do.
>
> I've also attached a program in syzkaller format.
> You can take a look at it, if you find it useful, I can start
> attaching them for subsequent reports.
Comparing it to thr() they look very close, at least for this one.
But when you cannot extract a reproducer, it will certainly help.
Thanks,
Marcelo
next prev parent reply other threads:[~2017-04-05 14:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-04 13:28 net/sctp: list double add warning in sctp_endpoint_add_asoc Andrey Konovalov
2017-04-04 17:29 ` Xin Long
2017-04-04 17:29 ` Xin Long
2017-04-04 21:14 ` Marcelo Ricardo Leitner
2017-04-04 21:14 ` Marcelo Ricardo Leitner
2017-04-05 10:48 ` Xin Long
2017-04-05 10:48 ` Xin Long
2017-04-05 12:44 ` Marcelo Ricardo Leitner
2017-04-05 12:44 ` Marcelo Ricardo Leitner
2017-04-05 14:03 ` Andrey Konovalov
2017-04-05 14:03 ` Andrey Konovalov
2017-04-05 14:02 ` Andrey Konovalov
2017-04-05 14:02 ` Andrey Konovalov
2017-04-05 14:22 ` Marcelo Ricardo Leitner [this message]
2017-04-05 14:22 ` Marcelo Ricardo Leitner
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