On 6/26/20 1:07 PM, Kees Cook wrote: > The implementation of __free_one() was accidentally placed inside a > CONFIG_NUMA #ifdef. Move it above. > > Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/lkml/7ff248c7-d447-340c-a8e2-8c02972aca70@xxxxxxxxxxxxx > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested Thanks. > --- > This a fix for slab-add-naive-detection-of-double-free.patch > --- > mm/slab.c | 20 ++++++++++---------- > 1 file changed, 10 insertions(+), 10 deletions(-) > > diff --git a/mm/slab.c b/mm/slab.c > index bbff6705ab2b..5ccb151a6e8f 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -588,6 +588,16 @@ static int transfer_objects(struct array_cache *to, > return nr; > } > > +/* &alien->lock must be held by alien callers. */ > +static __always_inline void __free_one(struct array_cache *ac, void *objp) > +{ > + /* Avoid trivial double-free. */ > + if (IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && > + WARN_ON_ONCE(ac->avail > 0 && ac->entry[ac->avail - 1] == objp)) > + return; > + ac->entry[ac->avail++] = objp; > +} > + > #ifndef CONFIG_NUMA > > #define drain_alien_cache(cachep, alien) do { } while (0) > @@ -749,16 +759,6 @@ static void drain_alien_cache(struct kmem_cache *cachep, > } > } > > -/* &alien->lock must be held by alien callers. */ > -static __always_inline void __free_one(struct array_cache *ac, void *objp) > -{ > - /* Avoid trivial double-free. */ > - if (IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && > - WARN_ON_ONCE(ac->avail > 0 && ac->entry[ac->avail - 1] == objp)) > - return; > - ac->entry[ac->avail++] = objp; > -} > - > static int __cache_free_alien(struct kmem_cache *cachep, void *objp, > int node, int page_node) > { > -- ~Randy
