Re: [PATCH] pipe: Fail cleanly when root tries F_SETPIPE_SZ withbig size

[Davidlohr Bueso]

On Fri, 2011-11-18 at 23:04 +0200, Pekka Enberg wrote:
> On Fri, Nov 18, 2011 at 10:04:34PM +0200, Sasha Levin wrote:
> >> +     if (nr_pages * sizeof(struct pipe_buffer) > KMALLOC_MAX_SIZE)
> >> +             return -ENOMEM;
> 
> On Fri, Nov 18, 2011 at 10:25 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> > nr_pages is unsigned long, sizeof is greater than 1, KMALLOC_MAX_SIZE is
> > unsigned long...  So write that check as KMALLOC_MAX_SIZE / sizeof > nr_pages
> 
> We could just use __GFP_NOWARN here and let kcalloc() deal with the
> overflow case.

Yep, that would seem the right place to deal with it, IMHO.

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