Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756158Ab3DWObn (ORCPT ); Tue, 23 Apr 2013 10:31:43 -0400 Received: from mx3-phx2.redhat.com ([209.132.183.24]:58951 "EHLO mx3-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755369Ab3DWObl (ORCPT ); Tue, 23 Apr 2013 10:31:41 -0400 Date: Tue, 23 Apr 2013 10:31:36 -0400 (EDT) From: Aaron Tomlin To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, cl@linux.com, penberg@kernel.org, Rik , Rafael Aquini Message-ID: <1014891011.990074.1366727496599.JavaMail.root@redhat.com> In-Reply-To: <1081382531.982691.1366726661820.JavaMail.root@redhat.com> Subject: [Patch v2] mm: slab: Verify the nodeid passed to ____cache_alloc_node MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.5.82.12] X-Mailer: Zimbra 8.0.3_GA_5664 (ZimbraWebClient - GC26 (Linux)/8.0.3_GA_5664) Thread-Topic: slab: Verify the nodeid passed to ____cache_alloc_node Thread-Index: E1uUKNmdgrejplje+FRlUAAEnw7pXQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1243 Lines: 42 Hi, This patch is in response to BZ#42967 [1]. Using VM_BUG_ON so it's used only when CONFIG_DEBUG_VM is set, given that ____cache_alloc_node() is a hot code path. Cheers, Aaron [1]: https://bugzilla.kernel.org/show_bug.cgi?id=42967 ---8<--- mm: slab: Verify the nodeid passed to ____cache_alloc_node If the nodeid is > num_online_nodes() this can cause an Oops and a panic(). The purpose of this patch is to assert if this condition is true to aid debugging efforts rather than some random NULL pointer dereference or page fault. Signed-off-by: Aaron Tomlin Reviewed-by: Rik van Riel slab.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/slab.c b/mm/slab.c index e7667a3..735e8bd 100644 --- a/mm/slab.c +++ b/mm/slab.c -3412,6 +3412,7 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, void *obj; int x; + VM_BUG_ON(nodeid > num_online_nodes()); l3 = cachep->nodelists[nodeid]; BUG_ON(!l3); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/