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Date:   Wed, 6 May 2020 10:08:49 -0400 (EDT)
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Oliver Neukum <oneukum@suse.com>
cc:     syzbot <syzbot+be5b5f86a162a6c281e6@syzkaller.appspotmail.com>,
        <andreyknvl@google.com>, <gregkh@linuxfoundation.org>,
        <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>,
        <syzkaller-bugs@googlegroups.com>, <zaitcev@redhat.com>
Subject: Re: KASAN: use-after-free Read in usblp_bulk_read
In-Reply-To: <1588756482.13662.20.camel@suse.com>
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On Wed, 6 May 2020, Oliver Neukum wrote:

> Am Donnerstag, den 30.04.2020, 11:11 -0400 schrieb Alan Stern:
> 
> > KASAN is documented.  The difficulty is that this race is obviously 
> > hard to trigger, and without the ability to reproduce it we can't run 
> > diagnostics to find the underlying cause.
> > 
> > We can't even ask syzbot to try running tests for us; without a valid 
> > reproducer it won't agree to rerun the original test program.
> 
> 
> Very well. We are not going to find it without exceptional luck. Yet
> there may be a real issue, too. We simply do not know. How about the
> attached patch?

It's okay with me (apart from the typo in the patch description: "UB").

Alan Stern