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	slub: Do not hold slub_lock when calling sysfs_slab_add()
sysfs_slab_add() calls various sysfs functions that actually may end up in userspace doing all sorts of things. Release the slub_lock after adding the kmem_cache structure to the list. At that point the address of the kmem_cache is not known so we are guaranteed exlusive access to the following modifications to the kmem_cache structure. If the sysfs_slab_add fails then reacquire the slub_lock to remove the kmem_cache structure from the list. Cc: <stable@vger.kernel.org> # 3.3+ Reported-by: Sasha Levin <levinsasha928@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
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					 1 changed files with 2 additions and 1 deletions
				
			
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					@ -3937,13 +3937,14 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
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		if (kmem_cache_open(s, n,
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							if (kmem_cache_open(s, n,
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				size, align, flags, ctor)) {
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									size, align, flags, ctor)) {
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			list_add(&s->list, &slab_caches);
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								list_add(&s->list, &slab_caches);
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								up_write(&slub_lock);
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			if (sysfs_slab_add(s)) {
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								if (sysfs_slab_add(s)) {
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									down_write(&slub_lock);
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				list_del(&s->list);
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									list_del(&s->list);
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				kfree(n);
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									kfree(n);
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				kfree(s);
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									kfree(s);
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				goto err;
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									goto err;
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			}
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								}
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			up_write(&slub_lock);
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			return s;
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								return s;
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		}
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							}
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		kfree(n);
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							kfree(n);
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