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Date: Thu, 21 Sep 2017 09:31:54 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Jaejoong Kim <climbbb.kim@gmail.com>,
        USB list <linux-usb@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Dmitry Vyukov <dvyukov@google.com>, Kostya Serebryany <kcc@google.com>,
        syzkaller <syzkaller@googlegroups.com>
Subject: Re: usb/core: slab-out-of-bounds read in cdc_parse_cdc_header
Message-ID: <20170921073154.GA11294@kroah.com>
References: <CAAeHK+y0HbzoNqcG_hZ+T==0MnFkxtMYZd_aUQ-R3gqK+VQcnw@mail.gmail.com>
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On Wed, Sep 20, 2017 at 04:45:08PM +0200, Andrey Konovalov wrote:
> Hi!
> 
> I've got the following crash while fuzzing the kernel with syzkaller.
> 
> On commit ebb2c2437d8008d46796902ff390653822af6cc4 (Sep 18).
> 
> It looks like cdc_parse_cdc_header() doesn't validate buflen before
> accessing buffer[1], buffer[2] and so on. The only check present is
> while (buflen > 0).

Ugh, you are right, let me go work on a patch, thanks for the report...