From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE70EC2BBE2 for ; Sun, 8 Dec 2019 13:57:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD876206F4 for ; Sun, 8 Dec 2019 13:57:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726786AbfLHN5O (ORCPT ); Sun, 8 Dec 2019 08:57:14 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60220 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726780AbfLHNyn (ORCPT ); Sun, 8 Dec 2019 08:54:43 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1idx1D-0007eh-8d; Sun, 08 Dec 2019 13:54:39 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1idx1C-0002Nc-5D; Sun, 08 Dec 2019 13:54:38 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Vasily Gorbik" , "Heiko Carstens" Date: Sun, 08 Dec 2019 13:53:24 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 40/72] s390/topology: avoid firing events before kobjs are created In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.79-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Vasily Gorbik commit f3122a79a1b0a113d3aea748e0ec26f2cb2889de upstream. arch_update_cpu_topology is first called from: kernel_init_freeable->sched_init_smp->sched_init_domains even before cpus has been registered in: kernel_init_freeable->do_one_initcall->s390_smp_init Do not trigger kobject_uevent change events until cpu devices are actually created. Fixes the following kasan findings: BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb40/0xee0 Read of size 8 at addr 0000000000000020 by task swapper/0/1 BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb36/0xee0 Read of size 8 at addr 0000000000000018 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: ([<0000000143c6db7e>] show_stack+0x14e/0x1a8) [<0000000145956498>] dump_stack+0x1d0/0x218 [<000000014429fb4c>] print_address_description+0x64/0x380 [<000000014429f630>] __kasan_report+0x138/0x168 [<0000000145960b96>] kobject_uevent_env+0xb36/0xee0 [<0000000143c7c47c>] arch_update_cpu_topology+0x104/0x108 [<0000000143df9e22>] sched_init_domains+0x62/0xe8 [<000000014644c94a>] sched_init_smp+0x3a/0xc0 [<0000000146433a20>] kernel_init_freeable+0x558/0x958 [<000000014599002a>] kernel_init+0x22/0x160 [<00000001459a71d4>] ret_from_fork+0x28/0x30 [<00000001459a71dc>] kernel_thread_starter+0x0/0x10 Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Ben Hutchings --- arch/s390/kernel/topology.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/s390/kernel/topology.c +++ b/arch/s390/kernel/topology.c @@ -266,7 +266,8 @@ int arch_update_cpu_topology(void) update_cpu_masks(); for_each_online_cpu(cpu) { dev = get_cpu_device(cpu); - kobject_uevent(&dev->kobj, KOBJ_CHANGE); + if (dev) + kobject_uevent(&dev->kobj, KOBJ_CHANGE); } return 1; }