From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E145C3AC01 for ; Mon, 11 Mar 2024 16:15:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710173749; cv=none; b=oRSGkUW4kmTqv1UX0ED11ej26o6bw9wOrbLcn1Hg4e7l55GMiPsihmvSJPpEMU9BFgORYPhnWZTqNcOtXIyMKRaFFtru0AmMq7vzlraNKpPAXmw7uIQkHRni+uVdjTWGT1cCMCFMm5JPGit2u4VoOEhSVReDyuTbXj55V99oDe8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710173749; c=relaxed/simple; bh=FiaMsB4YjZvOkuHyJ0lc36b2FtJ7u47S5pfvMXT2oBQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dKZqqvyrP0uSomuuVAhq8uVc4+w+pkwYK6Q91gRezN58vKTLUhsl6vK4iUgGOT54MjtHEJuEvRuXJrBZe9MkrKuyYXmvLBr5IcjbRWxuw+lKM78icE89CY7pD2EAG8oMY0DFBC+bZZIiwUrWNZW+jFgfKVbBl0aiTHcHIMA1jqs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZHVtjwLD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZHVtjwLD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F472C433C7; Mon, 11 Mar 2024 16:15:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710173748; bh=FiaMsB4YjZvOkuHyJ0lc36b2FtJ7u47S5pfvMXT2oBQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZHVtjwLDlqDfcNzWGphUV+T6/AF5pBJs1xaEKPRD8U05KOzll3dldIj1wim0l++qN F3mk0JF+XtJtkE9LLoR8H2xpP3eWocJfctAEEg0n0t+UfIhn9PGV463CSCYE1gLaTx P/jhpJ8BGhqLK0mffcHpCqkQT6wXVIrp8tUCCn84q+B2arcrjUgnehEMvE39E0GcWL Aeir0l38uwkprkwQ/PuBH8vaLObXh7YIDC3R/cXQAnDrJJJa1KnmEX3M5S+owsICAj Cdtvt76iy90/H2Q996bG/QQS/hE236HzRCwrljl2cqTaVNxE7xWPHdurRRcIRu0+zj K3p1D5C8jgd3w== Date: Mon, 11 Mar 2024 16:15:44 +0000 From: Lee Jones To: Sean Christopherson Cc: Michal Hocko , cve@kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Juergen Gross , Andrew Cooper Subject: Re: CVE-2023-52514: x86/reboot: VMCLEAR active VMCSes before emergency reboot Message-ID: <20240311161544.GS86322@google.com> References: <2024030251-CVE-2023-52514-c93d@gregkh> <20240311134202.GQ86322@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, 11 Mar 2024, Sean Christopherson wrote: > On Mon, Mar 11, 2024, Lee Jones wrote: > > On Mon, 11 Mar 2024, Michal Hocko wrote: > > > > > On Sat 02-03-24 22:52:59, Greg KH wrote: > > > > Description > > > > =========== > > > > > > > > In the Linux kernel, the following vulnerability has been resolved: > > > > > > > > x86/reboot: VMCLEAR active VMCSes before emergency reboot > > > > > > > > VMCLEAR active VMCSes before any emergency reboot, not just if the kernel > > > > may kexec into a new kernel after a crash. Per Intel's SDM, the VMX > > > > architecture doesn't require the CPU to flush the VMCS cache on INIT. If > > > > an emergency reboot doesn't RESET CPUs, cached VMCSes could theoretically > > > > be kept and only be written back to memory after the new kernel is booted, > > > > i.e. could effectively corrupt memory after reboot. > > > > > > > > Opportunistically remove the setting of the global pointer to NULL to make > > > > checkpatch happy. > > > > > > > > The Linux kernel CVE team has assigned CVE-2023-52514 to this issue. > > > > > > I do not really see the security aspect of this fix. Guests systems > > > shouldn't be able to trigger host reboot nor any untrusted entity should > > > on the host either or this would be a serious security hole. > > And not just any reboot either, this only comes into play with something like > `reboot -f`. Not to mention the impact of the bug is ridiculously theroetical > (I didn't tag the patch for stable@ for a reason). > > > > Or am I missing something? > > > > Thanks for reporting. > > > > If Sean and/or Paolo agree, we can revoke the CVE for you. > > Please do. No problem. All done for you: https://lore.kernel.org/all/20240311161318.1290374-2-lee@kernel.org/ Thanks again for the report. -- Lee Jones [李琼斯]