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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 1632CC3F2D2 for ; Mon, 2 Mar 2020 08:58:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D880E246BB for ; Mon, 2 Mar 2020 08:58:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="s+DXo/4Q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727060AbgCBI6j (ORCPT ); Mon, 2 Mar 2020 03:58:39 -0500 Received: from mail-lf1-f67.google.com ([209.85.167.67]:43392 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgCBI6j (ORCPT ); Mon, 2 Mar 2020 03:58:39 -0500 Received: by mail-lf1-f67.google.com with SMTP id s23so7324503lfs.10 for ; Mon, 02 Mar 2020 00:58:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9Al5IFuoY2rtnym3clzN0RNUtkS0nsC5av4BTRm+2H8=; b=s+DXo/4QB+gzeWecrfZeKjqe+Xn6/LZLwpd0Cm8a4dB5lSDFfBVny//mDtHl1R/ai8 3zYOJwaHiw3RUktuC7V69MDGGfL9r3ODivQhmIs9Ai6nASDMOWfrQzqsEMDwuu0xlDq7 jVajW5Wq0jZPWwjlhXf5Zw2G/7d+ykOVa9twrUwY/pSIiNebSJcnhLe0ERcCXgHhFD+d VNaIIOZUBRJvTs1GRk/t35WpDjgFhPR9hG/DA/W+daYuaGNNxt7FTMeYXuU6sKuAf2N+ WhgSUixDeoDy5jb7ZHjTQt7W0xbrAisaBWZ0Xe8fn9Ipbfy0IdoK9NTqBaRSAR3zlHZU jRkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9Al5IFuoY2rtnym3clzN0RNUtkS0nsC5av4BTRm+2H8=; b=Iz2HkczNkxq/MRbugdMEpiVtb9RApQlzBrWcIj7lTkP6dvZmAhUTH1HPqK/0OLuiQx MhRxFoMu6yDY21UeR6Ivs63/9nnHr7OH6u7pjBtdhJYFct/VmwI6ki/CMweriK7sHBPe 8HQHagpGit+1MYBkPWtc2AgGFc+iDK1hMVhjGny/mg7K1Gax0V8uQJQHNlYUB0D56/ON uGOD1TSBSH7K6fKBUwz4czw51cs0ySmX+JvcEdqfnZrkBkx/tJEwlXmFiK5+rHcR17cc 8B+hrLcxmjz3tbrwE8d9d/RP/d8u5vD8Q2toJRRQCybApZo6nkmbrEBi3ZuQ6KJmOhEs 1A/Q== X-Gm-Message-State: ANhLgQ2nCiXK9gO2DXDUSwJ+mm4lYi9PfvBj/ISQuKlJ+4+/IHzFJDe0 7W1BIPBJjEbV08VuDCGQ5BMWv6QxxckOqgaRRfjeVA== X-Google-Smtp-Source: ADFU+vsfA5pYmFGJV50ALCmK9XG6w4XRbq54i4YJwt2GzCZisxPtols/qSbqZqDlSvdlO2myf6Uo6NfLAsAVuWjSkNo= X-Received: by 2002:ac2:4d16:: with SMTP id r22mr9484343lfi.74.1583139517083; Mon, 02 Mar 2020 00:58:37 -0800 (PST) MIME-Version: 1.0 References: <1583133336-7832-1-git-send-email-wanpengli@tencent.com> In-Reply-To: <1583133336-7832-1-git-send-email-wanpengli@tencent.com> From: Naresh Kamboju Date: Mon, 2 Mar 2020 14:28:25 +0530 Message-ID: Subject: Re: [PATCH] KVM: X86: Fix dereference null cpufreq policy To: Wanpeng Li Cc: open list , kvm list , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2 Mar 2020 at 12:48, Wanpeng Li wrote: > > From: Wanpeng Li > > Naresh Kamboju reported: > > Linux version 5.6.0-rc4 (oe-user@oe-host) (gcc version > (GCC)) #1 SMP Sun Mar 1 22:59:08 UTC 2020 > kvm: no hardware support > BUG: kernel NULL pointer dereference, address: 000000000000028c > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: 0000 [#1] SMP NOPTI > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc4 #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > 04/01/2014 > RIP: 0010:kobject_put+0x12/0x1c0 > Call Trace: > cpufreq_cpu_put+0x15/0x20 > kvm_arch_init+0x1f6/0x2b0 > kvm_init+0x31/0x290 > ? svm_check_processor_compat+0xd/0xd > ? svm_check_processor_compat+0xd/0xd > svm_init+0x21/0x23 > do_one_initcall+0x61/0x2f0 > ? rdinit_setup+0x30/0x30 > ? rcu_read_lock_sched_held+0x4f/0x80 > kernel_init_freeable+0x219/0x279 > ? rest_init+0x250/0x250 > kernel_init+0xe/0x110 > ret_from_fork+0x27/0x50 > Modules linked in: > CR2: 000000000000028c > ---[ end trace 239abf40c55c409b ]--- > RIP: 0010:kobject_put+0x12/0x1c0 > > cpufreq policy which is get by cpufreq_cpu_get() can be NULL if it is failure, > this patch takes care of it. > > Fixes: aaec7c03de (KVM: x86: avoid useless copy of cpufreq policy) > Reported-by: Naresh Kamboju > Cc: Naresh Kamboju > Signed-off-by: Wanpeng Li Tested-by: Naresh Kamboju Applied this patch and test boot pass. - Naresh