From df3ae2c9941d38106afd67d7816b58f6dc7405e8 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Fri, 12 Mar 2021 21:07:53 -0800 Subject: [PATCH] kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations cache_alloc_debugcheck_after() performs checks on an object, including adjusting the returned pointer. None of this should apply to KFENCE objects. While for non-bulk allocations, the checks are skipped when we allocate via KFENCE, for bulk allocations cache_alloc_debugcheck_after() is called via cache_alloc_debugcheck_after_bulk(). Fix it by skipping cache_alloc_debugcheck_after() for KFENCE objects. Link: https://lkml.kernel.org/r/20210304205256.2162309-1-elver@google.com Signed-off-by: Marco Elver Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Konovalov Cc: Jann Horn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab.c b/mm/slab.c index 51fd424e0d6d..ae651bf540b7 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2992,7 +2992,7 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, gfp_t flags, void *objp, unsigned long caller) { WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO)); - if (!objp) + if (!objp || is_kfence_address(objp)) return objp; if (cachep->flags & SLAB_POISON) { check_poison_obj(cachep, objp); -- 2.20.1