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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 26 Mar 2019 09:20:40 +0100
Message-ID: <CAK8P3a1u_2gz=UieoNT7yOqSKFvFOXA34CAs7w+qouoQTjqDgQ@mail.gmail.com>
Subject: Re: [BACKPORT 4.4.y 04/25] USB: iowarrior: fix oops with malicious
 USB descriptors
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     "# 3.4.x" <stable@vger.kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        Josh Boyer <jwboyer@fedoraproject.org>,
        Ralf Spenneberg <ralf@spenneberg.net>,
        USB list <linux-usb@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Chunyan Zhang <chunyan.zhang@spreadtrum.com>,
        Baolin Wang <baolin.wang@spreadtrum.com>
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On Tue, Mar 26, 2019 at 2:23 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Mar 22, 2019 at 04:43:55PM +0100, Arnd Bergmann wrote:
> > From: Josh Boyer <jwboyer@fedoraproject.org>
> >
> > The iowarrior driver expects at least one valid endpoint.  If given
> > malicious descriptors that specify 0 for the number of endpoints,
> > it will crash in the probe function.  Ensure there is at least
> > one endpoint on the interface before using it.
> >
> > The full report of this issue can be found here:
> > http://seclists.org/bugtraq/2016/Mar/87
> >
> > Reported-by: Ralf Spenneberg <ralf@spenneberg.net>
> > Cc: stable <stable@vger.kernel.org>
> > Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > (cherry picked from commit 4ec0ef3a82125efc36173062a50624550a900ae0)
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> >  drivers/usb/misc/iowarrior.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
>
> This commit has been in the tree for a long time.  It was in the 4.4.7
> release, back in April 2016.  And then it was reverted in commit
> b7321e81fc36 ("USB: iowarrior: fix NULL-deref at probe") as it broke
> systems.  So why add it back, the correct functionality should be there
> today, right?

Sorry I missed that history. The script I used to identify patches noticed
that this patch was not applied, but I did not have a check for already-
reverted patches.

Chunyan, Baolin: it seems the spreadtrum 4.4 kernel got this wrong
as well, by backporting the patch again on top of 4.4.172. Can you check
the latest internal version for this?

       Arnd