Subject: Re: [regression] nf_iterate(), BUG: unable to handle kernel NULL pointer dereference

From: Matt Mackall <[email-masked]>
Date: Thu, 24 Jul 2008 08:11:49 -0500

On Thu, 2008-07-24 at 20:50 +0800, Herbert Xu wrote:
> On Thu, Jul 24, 2008 at 03:40:40PM +0300, Pekka Enberg wrote:
> >
> > Using ksize() for skbs will crash your kernel for some configurations
> > because calling that function for memory allocated with
> > kmem_cache_alloc() is not supported by all the allocators (well,
> > SLOB).
> 
> So how about fixing the interface so that it can return an error
> to indicate that the allocator doesn't support it?

You don't honestly expect people to correctly code to such a standard,
do you? People will assume that ksize never fails, they will be wrong,
and computers will die.

>  You're taking
> away an entire interface just because an underlying implementation
> that's used by a very small proportion of users doesn't do the
> right thing.

Umm, no. There were very few users to being with, so it was actually a
fairly large proportion. And that suggested the interface was a bad
idea.

-- 
Mathematics is the supreme nostalgia of our time.