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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 30EB7C32771 for ; Fri, 24 Jan 2020 09:52:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 07DC3206D5 for ; Fri, 24 Jan 2020 09:52:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859551; bh=/NX5NIOkf2dcZHN/pvg6AC1JzczEJW6QgsLSmhgP8wg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ODa69fg7KYHqznT2WVeAhyIKB7GOlrSPOym0za2beztmxzRK9YtYbgtS4x//D+Ue/ VDv7Lw1CbNoMjJUJbOT5S1NCetHc/aajrUDeFslT+SfEs9+YHoqdeAl/x3N8RTonUn YsKvc56TmTJAwNq8UfprqIm1Gg/wW4ra39WgZCys= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388166AbgAXJw3 (ORCPT ); Fri, 24 Jan 2020 04:52:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:54228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388152AbgAXJwY (ORCPT ); Fri, 24 Jan 2020 04:52:24 -0500 Received: from localhost (unknown [145.15.244.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4280F206D5; Fri, 24 Jan 2020 09:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859544; bh=/NX5NIOkf2dcZHN/pvg6AC1JzczEJW6QgsLSmhgP8wg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=siMgtrXLLl1CXqkJ09zFMfB+4owUwSrcVtguBqc6WAtMfDw58Y+Ztkr7fYqBlkW9X LY1nATOKBbQqaffgRSzPZbIm4xwC/1SDhzrDQPajzrnM+tx1owK6VV8CVhW40SBHYx CPQYwgBcOILjwzGsYtk2aO0SedqWq+/haTqT3w7w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Juergen Gross , Sasha Levin Subject: [PATCH 4.14 141/343] xen, cpu_hotplug: Prevent an out of bounds access Date: Fri, 24 Jan 2020 10:29:19 +0100 Message-Id: <20200124092938.553674683@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124092919.490687572@linuxfoundation.org> References: <20200124092919.490687572@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dan Carpenter [ Upstream commit 201676095dda7e5b31a5e1d116d10fc22985075e ] 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: Sasha Levin --- drivers/xen/cpu_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c index b1357aa4bc552..f192b6f42da9f 100644 --- a/drivers/xen/cpu_hotplug.c +++ b/drivers/xen/cpu_hotplug.c @@ -54,7 +54,7 @@ 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)) { -- 2.20.1