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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 4BAE3C43381 for ; Wed, 20 Mar 2019 15:50:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AC2721873 for ; Wed, 20 Mar 2019 15:50:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="Bv+2fjNr"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="TRz00Ypf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727389AbfCTPua (ORCPT ); Wed, 20 Mar 2019 11:50:30 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:33406 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726362AbfCTPu1 (ORCPT ); Wed, 20 Mar 2019 11:50:27 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 59FD0607C3; Wed, 20 Mar 2019 15:50:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553097025; bh=eJcfw1KaXjciYxRLIgRlNwUK0l3sz2sP031q6+VXl+w=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=Bv+2fjNrmyoVBVxlUuwV2h5D58RVnF7k6+226vKYNYJPzeWHLic/boYk7j9P7bfx7 NvwsvXvzTOwx5KdMT22ZTqmqxii3kO11XH5VCO4U/G1jhF66WWlyE1SecypAIV0UkR Ws3yZb9gwqyeXdWSKV7AiEQelq9JmfqRC9gPQXNc= Received: from [10.204.79.83] (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mojha@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id E0888606DB; Wed, 20 Mar 2019 15:50:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553097024; bh=eJcfw1KaXjciYxRLIgRlNwUK0l3sz2sP031q6+VXl+w=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=TRz00YpfzggTbp1D5x/z3TB5ylRbw6wzo+vTNrAFJW4YApo87tB+coa5du2g6Fo1a 7rOjBV5hrb9GH52falFQacSrJKCZcTpm2RN7Go9brO50kCpgo/cSoPteN241zOMtge LcUutYLysRdZ7jb7fgGwuZ/yz7xN++pqOz5TkLQA= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org E0888606DB Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=mojha@codeaurora.org Subject: Re: [PATCH] hyperv: a potential NULL pointer dereference To: Kangjie Lu Cc: pakki001@umn.edu, "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Sasha Levin , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190314054651.1315-1-kjlu@umn.edu> From: Mukesh Ojha Message-ID: <24cbb2df-6510-2ed8-deca-670ea934db68@codeaurora.org> Date: Wed, 20 Mar 2019 21:20:13 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190314054651.1315-1-kjlu@umn.edu> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/14/2019 11:16 AM, Kangjie Lu wrote: > In case alloc_page, the fix returns -ENOMEM to avoid the potential > NULL pointer dereference. > > Signed-off-by: Kangjie Lu > --- > arch/x86/hyperv/hv_init.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > index 7abb09e2eeb8..dfdb4ce1ae9c 100644 > --- a/arch/x86/hyperv/hv_init.c > +++ b/arch/x86/hyperv/hv_init.c > @@ -102,9 +102,13 @@ static int hv_cpu_init(unsigned int cpu) > u64 msr_vp_index; > struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()]; > void **input_arg; > + struct page *pg; > > input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); > - *input_arg = page_address(alloc_page(GFP_KERNEL)); > + pg = alloc_page(GFP_KERNEL); > + if (unlikely(!pg)) > + return -ENOMEM; > + *input_arg = page_address(pg); > > hv_get_vp_index(msr_vp_index); Looks good to me. Reviewed-by: Mukesh Ojha Thanks. Mukesh >