Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932297AbdHWQvF (ORCPT ); Wed, 23 Aug 2017 12:51:05 -0400 Received: from mail-pf0-f179.google.com ([209.85.192.179]:36089 "EHLO mail-pf0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754129AbdHWQvD (ORCPT ); Wed, 23 Aug 2017 12:51:03 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (1.0) Subject: Re: [PATCH] x86/nmi/64: avoid passing user space rsp of pt_regs to nmi handler From: Andy Lutomirski X-Mailer: iPhone Mail (14G60) In-Reply-To: <20170823152059.aix2zb24xsndfntq@treble> Date: Wed, 23 Aug 2017 09:51:01 -0700 Cc: oliver yang , yang oliver , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "luto@kernel.org" , "x86@kernel.org" , "rostedt@goodmis.org" , "linux-kernel@vger.kernel.org" Message-Id: <39192236-BD33-47C1-AB14-F2FE2FF74566@amacapital.net> References: <20170822175115.k3tdjlkltua7lkiu@treble> <20170823152059.aix2zb24xsndfntq@treble> To: Josh Poimboeuf Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v7NGp9cO028939 Content-Length: 414 Lines: 3 To avoid further wasting time solving this wrong: NAK. pt_regs is the actual interrupted state, not some oddly sanitized version thereof. NMI isn't even the only way you can have a weird pt_regs like this. It seems that some older kernels contain bugs where they incorrectly assume that regs->rsp is a valid pointer. Why don't you write a patch for *that * and send it to lkml, us, and stable@vger.kernel.org.