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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 20163C48BDE for ; Sun, 7 Jul 2019 19:41:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 048A520659 for ; Sun, 7 Jul 2019 19:41:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728144AbfGGTlp (ORCPT ); Sun, 7 Jul 2019 15:41:45 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57848 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727643AbfGGTiP (ORCPT ); Sun, 7 Jul 2019 15:38:15 -0400 Received: from 94.197.121.43.threembb.co.uk ([94.197.121.43] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hkCzC-0006jD-K9; Sun, 07 Jul 2019 20:38:10 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hkCz8-0005fA-C8; Sun, 07 Jul 2019 20:38:06 +0100 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 , "Dan Carpenter" , "Juergen Gross" Date: Sun, 07 Jul 2019 17:54:17 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 109/129] xen, cpu_hotplug: Prevent an out of bounds access In-Reply-To: X-SA-Exim-Connect-IP: 94.197.121.43 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.70-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 201676095dda7e5b31a5e1d116d10fc22985075e upstream. The "cpu" variable comes from the sscanf() so Smatch marks it as untrusted data. We can't pass a higher value than "nr_cpu_ids" to cpu_possible() or it results in an out of bounds access. Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging") Signed-off-by: Dan Carpenter Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Ben Hutchings --- drivers/xen/cpu_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/xen/cpu_hotplug.c +++ b/drivers/xen/cpu_hotplug.c @@ -47,7 +47,7 @@ static int vcpu_online(unsigned int cpu) } static void vcpu_hotplug(unsigned int cpu) { - if (!cpu_possible(cpu)) + if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) return; switch (vcpu_online(cpu)) {