From 0142eae3ae15b9b9f0ae2a8e68e3c8dc347a2394 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 15 Mar 2016 14:53:44 -0700 Subject: [PATCH] mm: kmemcheck skip object if slab allocation failed In the SLAB allocator kmemcheck_slab_alloc() is guarded against being called in case the object is NULL. In SLUB allocator this NULL pointer invocation can happen, which seems like an oversight. Move the NULL pointer check into kmemcheck code (kmemcheck_slab_alloc) so the check gets moved out of the fastpath, when not compiled with CONFIG_KMEMCHECK. This is a step towards sharing post_alloc_hook between SLUB and SLAB, because slab_post_alloc_hook() does not perform this check before calling kmemcheck_slab_alloc(). Signed-off-by: Jesper Dangaard Brouer Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kmemcheck.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c index cab58bb592d8..6f4f424037c0 100644 --- a/mm/kmemcheck.c +++ b/mm/kmemcheck.c @@ -60,6 +60,9 @@ void kmemcheck_free_shadow(struct page *page, int order) void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object, size_t size) { + if (unlikely(!object)) /* Skip object if allocation failed */ + return; + /* * Has already been memset(), which initializes the shadow for us * as well. -- 2.30.2