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Subject: Re: [PATCH] slub: Potential stack overflow
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka J Enberg <penberg@cs.helsinki.fi>,
       linux-kernel <linux-kernel@vger.kernel.org>
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Date: Wed, 24 Mar 2010 20:22:08 +0100
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Le mercredi 24 mars 2010 à 14:16 -0500, Christoph Lameter a écrit :
> On Wed, 24 Mar 2010, Eric Dumazet wrote:
> 
> > I discovered that we can overflow stack if CONFIG_SLUB_DEBUG=y and use
> > slabs with many objects, since list_slab_objects() and process_slab()
> > use DECLARE_BITMAP(map, page->objects);
> 
> Maybe we better allocate the bitmap via kmalloc then.
> 

Hmm...

Are we allowed to nest in these two functions ?

GFP_KERNEL, GFP_ATOMIC ?

These are debugging functions, what happens if kmalloc() returns NULL ?