Re: [PATCH v2 08/20] randstruct: Whitelist NIU struct page overloading

[Kees Cook]

On Sun, May 28, 2017 at 1:15 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> On Fri, May 26, 2017 at 01:17:12PM -0700, Kees Cook wrote:
>> The NIU ethernet driver intentionally stores a page struct pointer on
>> top of the "mapping" field. Whitelist this case:
>>
>> drivers/net/ethernet/sun/niu.c: In function âniu_rx_pkt_ignoreâ:
>> drivers/net/ethernet/sun/niu.c:3402:10: note: found mismatched ssa struct pointer types: âstruct pageâ and âstruct address_spaceâ
>>
>>     *link = (struct page *) page->mapping;
>>     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
>> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>
> The driver really needs to stop doing this anyway.  It would be good
> to send this out to linux-mm and netdev to come up with a better scheme.

Added to To. :) I couldn't understand why it was doing what it was
doing, hence the whitelist entry.

-Kees

-- 
Kees Cook
Pixel Security