Commit df3ae2c9 authored by Marco Elver's avatar Marco Elver Committed by Linus Torvalds
Browse files

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: default avatarMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 702b16d7

mm/slab.c

+1 −1
Original line number Diff line number Diff line
@@ -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);