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

[Greg Kroah-Hartman]

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?

thanks,

greg k-h