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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 68CAFC433DF for ; Wed, 27 May 2020 00:12:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 520262088E for ; Wed, 27 May 2020 00:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbgE0AMP (ORCPT ); Tue, 26 May 2020 20:12:15 -0400 Received: from mga04.intel.com ([192.55.52.120]:14717 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725969AbgE0AMO (ORCPT ); Tue, 26 May 2020 20:12:14 -0400 IronPort-SDR: DUsAlBE1/cbQEr8X+PBFtbDIy0V8b40WT/FunzzkusoxVmFEHCkM+1/OyY/yGD3carKpYHmCX9 TQ+Vxve+fkYQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 May 2020 17:12:14 -0700 IronPort-SDR: KQnRZ+5k13psFrnBoq88rIvT+3D2Ihvhk0t6qttIJX/a2X43NEjNGfsHwVkQ/uwwamVkqckvKK WaU0dtnyT74A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,439,1583222400"; d="scan'208";a="345350156" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.152]) by orsmga001.jf.intel.com with ESMTP; 26 May 2020 17:12:13 -0700 Date: Tue, 26 May 2020 17:12:13 -0700 From: Sean Christopherson To: syzbot Cc: bp@alien8.de, eesposit@redhat.com, gregkh@linuxfoundation.org, hpa@zytor.com, jmattson@google.com, joro@8bytes.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, pbonzini@redhat.com, rafael@kernel.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, vkuznets@redhat.com, wanpengli@tencent.com, x86@kernel.org Subject: Re: kernel BUG at arch/x86/kvm/mmu/mmu.c:LINE! (2) Message-ID: <20200527001213.GA31696@linux.intel.com> References: <000000000000935ffd05a6939060@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000935ffd05a6939060@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, May 26, 2020 at 02:13:19PM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: c11d28ab Add linux-next specific files for 20200522 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=153b5016100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=3f6dbdea4159fb66 > dashboard link: https://syzkaller.appspot.com/bug?extid=904752567107eefb728c > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11510cba100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=129301e2100000 > > The bug was bisected to: > > commit 63d04348371b7ea4a134bcf47c79763d969e9168 > Author: Paolo Bonzini > Date: Tue Mar 31 22:42:22 2020 +0000 > > KVM: x86: move kvm_create_vcpu_debugfs after last failure point > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1226e8ee100000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=1126e8ee100000 > console output: https://syzkaller.appspot.com/x/log.txt?x=1626e8ee100000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+904752567107eefb728c@syzkaller.appspotmail.com > Fixes: 63d04348371b ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point") > > L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. > ------------[ cut here ]------------ > kernel BUG at arch/x86/kvm/mmu/mmu.c:3722! The bisection has a completely different signature, it's likely a different bug. I'll take a look at both.