Re: [PATCH] slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU

From: Pekka Enberg
Date: Thu Sep 03 2009 - 15:48:19 EST


On Thu, Sep 3, 2009 at 5:18 PM, Eric Dumazet<eric.dumazet@xxxxxxxxx> wrote:
> Here is the second patch (RCU thing). Stable candidate
>
> [PATCH] slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU
>
> kmem_cache_destroy() should call rcu_barrier() *after* kmem_cache_close()
> and *before* sysfs_slab_remove() or risk rcu_free_slab()
> being called after kmem_cache is deleted (kfreed).
>
> rmmod nf_conntrack can crash the machine because it has to
> kmem_cache_destroy() a SLAB_DESTROY_BY_RCU enabled cache.

Do we have a bugzilla URL for this?

> Reported-by: Zdenek Kabelac <zdenek.kabelac@xxxxxxxxx>
> Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

OK, this is in for-next now and queued for 2.6.31. If you guys want to
fix this in a different way, lets do that in 2.6.32.

Pekka
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