On Mon, 13 Jun 2022 at 22:15, <andrey.konovalov@xxxxxxxxx> wrote: > > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > __kasan_metadata_size() calculates the size of the redzone for objects > in a slab cache. > > When accounting for presence of kasan_free_meta in the redzone, this > function only compares free_meta_offset with 0. But free_meta_offset could > also be equal to KASAN_NO_FREE_META, which indicates that kasan_free_meta > is not present at all. > > Add a comparison with KASAN_NO_FREE_META into __kasan_metadata_size(). > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > --- > > This is a minor fix that only affects slub_debug runs, so it is probably > not worth backporting. > --- > mm/kasan/common.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > index c40c0e7b3b5f..968d2365d8c1 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -223,8 +223,9 @@ size_t __kasan_metadata_size(struct kmem_cache *cache) > return 0; > return (cache->kasan_info.alloc_meta_offset ? > sizeof(struct kasan_alloc_meta) : 0) + > - (cache->kasan_info.free_meta_offset ? > - sizeof(struct kasan_free_meta) : 0); > + ((cache->kasan_info.free_meta_offset && > + cache->kasan_info.free_meta_offset != KASAN_NO_FREE_META) ? > + sizeof(struct kasan_free_meta) : 0); > } > > struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache, > -- > 2.25.1 > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/91406e5f2a1c0a1fddfc4e7f17df22fda852591c.1655150842.git.andreyknvl%40google.com.
