Re: [BACKPORT 4.4.y 04/25] USB: iowarrior: fix oops with malicious USB descriptors

From: Baolin Wang
Date: Tue Mar 26 2019 - 05:36:00 EST


On Tue, 26 Mar 2019 at 16:21, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Tue, Mar 26, 2019 at 2:23 AM Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Fri, Mar 22, 2019 at 04:43:55PM +0100, Arnd Bergmann wrote:
> > > From: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx>
> > >
> > > 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@xxxxxxxxxxxxxx>
> > > Cc: stable <stable@xxxxxxxxxxxxxxx>
> > > Signed-off-by: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx>
> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > (cherry picked from commit 4ec0ef3a82125efc36173062a50624550a900ae0)
> > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > > ---
> > > 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?

Yes, I saw this patch in our 4.4 kernel.

Orson, we should revert this patch from our kernel as Greg mentioned.

--
Baolin Wang
Best Regards