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Date:   Wed, 6 Oct 2021 13:10:00 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        Doug Ledford <dledford@redhat.com>,
        syzbot <syzbot+3a992c9e4fd9f0e6fd0e@syzkaller.appspotmail.com>,
        RDMA mailing list <linux-rdma@vger.kernel.org>,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] BUG: RESTRACK detected leak of resources
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 <20211004131516.GV3544071@ziepe.ca>
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On Mon, Oct 04, 2021 at 10:15:16AM -0300, Jason Gunthorpe wrote:
> On Mon, Oct 04, 2021 at 02:42:11PM +0200, Dmitry Vyukov wrote:
> > On Mon, 4 Oct 2021 at 12:45, syzbot
> > <syzbot+3a992c9e4fd9f0e6fd0e@syzkaller.appspotmail.com> wrote:
> > >
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit:    c7b4d0e56a1d Add linux-next specific files for 20210930
> > > git tree:       linux-next
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=104be6cb300000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=c9a1f6685aeb48bd
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=3a992c9e4fd9f0e6fd0e
> > > compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > >
> > > Unfortunately, I don't have any reproducer for this issue yet.
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: syzbot+3a992c9e4fd9f0e6fd0e@syzkaller.appspotmail.com
> > 
> > +RESTRACK maintainers
> > 
> > (it would also be good if RESTRACK would print a more standard oops
> > with stack/filenames, so that testing systems can attribute issues to
> > files/maintainers).
> 
> restrack certainly should trigger a WARN_ON to stop the kernel.. But I
> don't know what stack track would be useful here. The culprit is
> always the underlying driver, not the core code..

We had WARN_ON() in early versions, but it didn't give us anything
except spammed dmesg, so I changed it to more lighter version.

> 
> Anyhow, this report is either rxe or rds by the look of it.
> 
> Jason