From: Parav Pandit <parav@mellanox.com>
To: Jason Gunthorpe <jgg@ziepe.ca>, Eric Biggers <ebiggers@kernel.org>
Cc: Doug Ledford <dledford@redhat.com>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"dasaratharaman.chandramouli@intel.com"
<dasaratharaman.chandramouli@intel.com>,
Leon Romanovsky <leonro@mellanox.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Mark Bloch <markb@mellanox.com>, Moni Shoua <monis@mellanox.com>,
"syzkaller-bugs@googlegroups.com"
<syzkaller-bugs@googlegroups.com>,
syzbot <syzbot+29ee8f76017ce6cf03da@syzkaller.appspotmail.com>
Subject: RE: [RDMA bug] KASAN: use-after-free Read in __list_del_entry_valid (4)
Date: Thu, 23 Aug 2018 16:39:29 +0000 [thread overview]
Message-ID: <VI1PR0501MB22714BE9A34FA333671A0623D1370@VI1PR0501MB2271.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <20180823145458.GC9366@ziepe.ca>
> -----Original Message-----
> From: Jason Gunthorpe <jgg@ziepe.ca>
> Sent: Thursday, August 23, 2018 9:55 AM
> To: Eric Biggers <ebiggers@kernel.org>
> Cc: Doug Ledford <dledford@redhat.com>; linux-rdma@vger.kernel.org;
> dasaratharaman.chandramouli@intel.com; Leon Romanovsky
> <leonro@mellanox.com>; linux-kernel@vger.kernel.org; Mark Bloch
> <markb@mellanox.com>; Moni Shoua <monis@mellanox.com>; Parav Pandit
> <parav@mellanox.com>; syzkaller-bugs@googlegroups.com; syzbot
> <syzbot+29ee8f76017ce6cf03da@syzkaller.appspotmail.com>
> Subject: Re: [RDMA bug] KASAN: use-after-free Read in __list_del_entry_valid
> (4)
>
> On Wed, Aug 22, 2018 at 11:16:31PM -0700, Eric Biggers wrote:
> > Hello RDMA / InfiniBand maintainers,
> >
> > This is an RDMA bug and it still occurs on Linus' tree as of today
> > (commit 815f0ddb346c1960).
> >
> > I've also simplified the reproducer for it; see below after the original report.
> > Apparently it involves a race between RDMA_USER_CM_CMD_RESOLVE_IP
> and
> > RDMA_USER_CM_CMD_LISTEN.
>
> That is an amazing reproducer!
>
> I have a feeling this is the same cause as all the other syzkaller bugs in this code:
> lack of any sane locking at all :\
>
> We've talked about chucking a big lock around this whole thing, but nobody has
> done it yet.. It isn't so simple.
>
I had some code in which reduces three locks (handler_lock, qp_mutex, id_lock) to single mutex to protect the cm_id and protects every exported symbol of rdmacm which works on cm_id.
But not ready enough to post it as patch yet. Lot of tests required before I get there and some refactor too before that.
> Jason
next prev parent reply other threads:[~2018-08-23 16:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-26 0:01 KASAN: use-after-free Read in __list_del_entry_valid (4) syzbot
2018-03-26 3:43 ` syzbot
2018-08-23 6:16 ` [RDMA bug] " Eric Biggers
2018-08-23 14:54 ` Jason Gunthorpe
2018-08-23 16:39 ` Parav Pandit [this message]
2018-08-23 16:55 ` Doug Ledford
2018-08-23 17:14 ` Parav Pandit
2018-08-23 17:17 ` Jason Gunthorpe
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