Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933443AbdCaQke (ORCPT ); Fri, 31 Mar 2017 12:40:34 -0400 Received: from mail-pg0-f47.google.com ([74.125.83.47]:33714 "EHLO mail-pg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933159AbdCaQkc (ORCPT ); Fri, 31 Mar 2017 12:40:32 -0400 Date: Fri, 31 Mar 2017 09:40:28 -0700 From: Kees Cook To: Andrew Morton Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm: Add additional consistency check Message-ID: <20170331164028.GA118828@beast> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 637 Lines: 27 As found in PaX, this adds a cheap check on heap consistency, just to notice if things have gotten corrupted in the page lookup. Signed-off-by: Kees Cook --- mm/slab.h | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/slab.h b/mm/slab.h index 65e7c3fcac72..64447640b70c 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -384,6 +384,7 @@ static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) return s; page = virt_to_head_page(x); + BUG_ON(!PageSlab(page)); cachep = page->slab_cache; if (slab_equal_or_root(cachep, s)) return cachep; -- 2.7.4 -- Kees Cook Pixel Security