From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Michal Hocko <mhocko@suse.cz>,
David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
sergey.senozhatsky.work@gmail.com,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: [RFC][PATCH 1/5] mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()
Date: Tue, 9 Jun 2015 21:04:49 +0900 [thread overview]
Message-ID: <1433851493-23685-2-git-send-email-sergey.senozhatsky@gmail.com> (raw)
In-Reply-To: <1433851493-23685-1-git-send-email-sergey.senozhatsky@gmail.com>
kmem_cache_destroy() does not tolerate a NULL kmem_cache pointer
argument and performs a NULL-pointer dereference. This requires
additional attention and effort from developers/reviewers and
forces all kmem_cache_destroy() callers (200+ as of 4.1) to do
a NULL check
if (cache)
kmem_cache_destroy(cache);
Or, otherwise, be invalid kmem_cache_destroy() users.
Tweak kmem_cache_destroy() and NULL-check the pointer there.
Proposed by Andrew Morton.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
LKML-reference: https://lkml.org/lkml/2015/6/8/583
---
mm/slab_common.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8873985..ea69b13 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -641,6 +641,9 @@ void kmem_cache_destroy(struct kmem_cache *s)
bool need_rcu_barrier = false;
bool busy = false;
+ if (unlikely(!s))
+ return;
+
BUG_ON(!is_root_cache(s));
get_online_cpus();
--
2.4.3.368.g7974889
next prev parent reply other threads:[~2015-06-09 12:06 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-09 12:04 [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions Sergey Senozhatsky
2015-06-09 12:04 ` Sergey Senozhatsky [this message]
2015-06-17 23:14 ` [RFC][PATCH 1/5] mm/slab_common: allow NULL cache pointer in kmem_cache_destroy() David Rientjes
2015-06-17 23:52 ` Sergey Senozhatsky
2015-06-19 15:50 ` Julia Lawall
2015-08-06 14:21 ` Sergey Senozhatsky
2015-08-06 14:27 ` Julia Lawall
2015-08-06 14:29 ` Sergey Senozhatsky
2015-06-20 16:25 ` Julia Lawall
2015-07-16 8:26 ` Sergey Senozhatsky
2015-06-09 12:04 ` [RFC][PATCH 2/5] mm/mempool: allow NULL `pool' pointer in mempool_destroy() Sergey Senozhatsky
2015-06-17 23:21 ` David Rientjes
2015-06-17 23:54 ` Sergey Senozhatsky
2015-06-09 12:04 ` [RFC][PATCH 3/5] mm/dmapool: allow NULL `pool' pointer in dma_pool_destroy() Sergey Senozhatsky
2015-06-17 23:22 ` David Rientjes
2015-06-09 12:04 ` [RFC][PATCH 4/5] mm/zpool: allow NULL `zpool' pointer in zpool_destroy_pool() Sergey Senozhatsky
2015-06-10 20:59 ` Dan Streetman
2015-06-10 23:58 ` Sergey Senozhatsky
2015-06-11 0:48 ` Joe Perches
2015-06-11 0:59 ` Sergey Senozhatsky
2015-06-11 1:01 ` Dan Streetman
2015-06-09 12:04 ` [RFC][PATCH 5/5] mm/zsmalloc: allow NULL `pool' pointer in zs_destroy_pool() Sergey Senozhatsky
2015-06-09 21:25 ` [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions Andrew Morton
2015-06-10 0:06 ` Joe Perches
2015-06-10 4:39 ` [PATCH] checkpatch: Add some <foo>_destroy functions to NEEDLESS_IF tests Joe Perches
2015-06-10 5:52 ` [PATCH V2] " Joe Perches
2015-06-10 10:18 ` Sergey Senozhatsky
2015-06-11 9:41 ` Julia Lawall
2015-06-11 9:51 ` Sergey Senozhatsky
2015-06-11 9:55 ` Julia Lawall
2015-07-14 23:03 ` Andrew Morton
2015-07-15 0:27 ` Sergey Senozhatsky
2015-06-10 5:46 ` [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions Julia Lawall
2015-06-10 6:41 ` Sergey Senozhatsky
2015-06-10 6:44 ` Julia Lawall
2015-06-10 6:52 ` Sergey Senozhatsky
2015-06-10 1:11 ` Christoph Lameter
2015-06-10 1:51 ` Andrew Morton
2015-06-10 2:00 ` Christoph Lameter
2015-06-10 2:17 ` Andrew Morton
2015-06-10 4:47 ` Joe Perches
2015-06-11 17:26 ` Christoph Lameter
2015-06-11 17:40 ` Andrew Morton
2015-06-10 2:04 ` Sergey Senozhatsky
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