Messages in this thread | | | Date | Fri, 7 Jul 2017 13:23:51 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] slub: make sure struct kmem_cache_node is initialized before publication |
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On Fri, 7 Jul 2017 10:34:08 +0200 Alexander Potapenko <glider@google.com> wrote:
> --- a/mm/slub.c > +++ b/mm/slub.c > @@ -3389,8 +3389,8 @@ static int init_kmem_cache_nodes(struct kmem_cache *s) > return 0; > } > > - s->node[node] = n; > init_kmem_cache_node(n); > + s->node[node] = n; > } > return 1; > }
If this matters then I have bad feelings about free_kmem_cache_nodes():
static void free_kmem_cache_nodes(struct kmem_cache *s) { int node; struct kmem_cache_node *n;
for_each_kmem_cache_node(s, node, n) { kmem_cache_free(kmem_cache_node, n); s->node[node] = NULL; } }
Inviting a use-after-free? I guess not, as there should be no way to look up these items at this stage.
Could the slab maintainers please take a look at these and also have a think about Alexander's READ_ONCE/WRITE_ONCE question?
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