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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 1B948C4332E for ; Thu, 19 Mar 2020 17:53:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F19C22072D for ; Thu, 19 Mar 2020 17:53:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727432AbgCSRxG (ORCPT ); Thu, 19 Mar 2020 13:53:06 -0400 Received: from mga04.intel.com ([192.55.52.120]:57567 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726867AbgCSRxG (ORCPT ); Thu, 19 Mar 2020 13:53:06 -0400 IronPort-SDR: jgJJQVo8LfQqtnIUZ+0fs3gfQHd0eWE3O9PSL7V3pI535PTnWJsdSgfnDxFauplT3A851uF9hO Onv++lwmQvuw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2020 10:53:00 -0700 IronPort-SDR: oVW2A+P+v8UZ1v3CjfxeeilfiC243H2UiYB328K62YrscNe2463SDKKZlfrmRo9aAv28qSH7AH 62hKZS4TO+Dw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,572,1574150400"; d="scan'208";a="356107676" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.202]) by fmsmga001.fm.intel.com with ESMTP; 19 Mar 2020 10:52:59 -0700 Date: Thu, 19 Mar 2020 10:52:59 -0700 From: Sean Christopherson To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, syzbot+00be5da1d75f1cc95f6b@syzkaller.appspotmail.com Subject: Re: [PATCH] KVM: x86: remove bogus user-triggerable WARN_ON Message-ID: <20200319175259.GE11305@linux.intel.com> References: <20200319174318.20752-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200319174318.20752-1-pbonzini@redhat.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 Thu, Mar 19, 2020 at 01:43:18PM -0400, Paolo Bonzini wrote: > The WARN_ON is essentially comparing a user-provided value with 0. It is > trivial to trigger it just by passing garbage to KVM_SET_CLOCK. Guests > can break if you do so, but if it hurts when you do like this just do not > do it. > > Reported-by: syzbot+00be5da1d75f1cc95f6b@syzkaller.appspotmail.com > Fixes: 9446e6fce0ab ("KVM: x86: fix WARN_ON check of an unsigned less than zero") > Cc: Sean Christopherson > Signed-off-by: Paolo Bonzini > --- Reviewed-by: Sean Christopherson