Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754613Ab3GBTMN (ORCPT ); Tue, 2 Jul 2013 15:12:13 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58280 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754024Ab3GBTML (ORCPT ); Tue, 2 Jul 2013 15:12:11 -0400 Date: Tue, 2 Jul 2013 12:12:10 -0700 From: Andrew Morton To: Tetsuo Handa Cc: cl@linux.com, glommer@parallels.com, penberg@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [linux-next-20130422] Bug in SLAB? Message-Id: <20130702121210.121c8e2df7745994174c53e1@linux-foundation.org> In-Reply-To: <201307022149.HEB90128.QFJFHOLMVtFSOO@I-love.SAKURA.ne.jp> References: <201305071938.DAC81273.HOSJOFFOQLtMFV@I-love.SAKURA.ne.jp> <0000013e7f651028-9a57bc30-4148-4aba-a0e6-737b83bf2458-000000@email.amazonses.com> <20130701130903.61459f57f4ba31e282065001@linux-foundation.org> <201307020645.JGI86434.FFHOLOSFOtJVMQ@I-love.SAKURA.ne.jp> <20130701145356.f9c43875890d1aec90fe1ad9@linux-foundation.org> <201307022149.HEB90128.QFJFHOLMVtFSOO@I-love.SAKURA.ne.jp> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2176 Lines: 59 On Tue, 2 Jul 2013 21:49:26 +0900 Tetsuo Handa wrote: > Some architectures (e.g. powerpc built with CONFIG_PPC_256K_PAGES=y > CONFIG_FORCE_MAX_ZONEORDER=11) get PAGE_SHIFT + MAX_ORDER > 26. > > In 3.10 kernels, CONFIG_LOCKDEP=y with PAGE_SHIFT + MAX_ORDER > 26 makes > init_lock_keys() dereference beyond kmalloc_caches[26]. > This leads to an unbootable system (kernel panic at initializing SLAB) > if one of kmalloc_caches[26...PAGE_SHIFT+MAX_ORDER-1] is not NULL. > > Fix this by making sure that init_lock_keys() does not dereference beyond > kmalloc_caches[26] arrays. Nice, thanks. Pekka, please grab. From: Christoph Lameter Subject: slab: fix init_lock_keys Some architectures (e.g. powerpc built with CONFIG_PPC_256K_PAGES=y CONFIG_FORCE_MAX_ZONEORDER=11) get PAGE_SHIFT + MAX_ORDER > 26. In 3.10 kernels, CONFIG_LOCKDEP=y with PAGE_SHIFT + MAX_ORDER > 26 makes init_lock_keys() dereference beyond kmalloc_caches[26]. This leads to an unbootable system (kernel panic at initializing SLAB) if one of kmalloc_caches[26...PAGE_SHIFT+MAX_ORDER-1] is not NULL. Fix this by making sure that init_lock_keys() does not dereference beyond kmalloc_caches[26] arrays. Signed-off-by: Christoph Lameter Reported-by: Tetsuo Handa Cc: Pekka Enberg Cc: [3.10.x] Signed-off-by: Andrew Morton --- mm/slab.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN mm/slab.c~slab-fix-init_lock_keys mm/slab.c --- a/mm/slab.c~slab-fix-init_lock_keys +++ a/mm/slab.c @@ -565,7 +565,7 @@ static void init_node_lock_keys(int q) if (slab_state < UP) return; - for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) { + for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) { struct kmem_cache_node *n; struct kmem_cache *cache = kmalloc_caches[i]; _ -- 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/