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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 DA191C43387 for ; Fri, 11 Jan 2019 10:03:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7D3221848 for ; Fri, 11 Jan 2019 10:03:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y8ZzuVWz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731591AbfAKKC7 (ORCPT ); Fri, 11 Jan 2019 05:02:59 -0500 Received: from merlin.infradead.org ([205.233.59.134]:56254 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727653AbfAKKC7 (ORCPT ); Fri, 11 Jan 2019 05:02:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=pcTMygEALRHllzFZxAMVlB56K3XYfhrHxK7e9gi5eDs=; b=Y8ZzuVWzO1AebgDhpKIBTWlOr fH8MlCNm2sUuAlNutbHFS+XCUWbkOUBEsGQmxmppbQBYZ3j+IVOSZiOIgbuGuuPW4nBITngLHGcVx dLdPkGmqcskPVAQP90N2PCCFLIvj1V/5rBvXppD1qzYplCNkpmS41zACybBQxjx6oEqSWfKLis4mQ h+sUoFatpVDvrDfHMiubofyD/CLlzgZuEfGALfKtfvBsM3vQOrp+7C6vvxZp4Md+GtiNOS2CF+vDo YiT5sCVUGahWyMz2acqlbAbPlA3RKXVoYph2EL5JRfqnMRQ1MMSVdQfhKD8RfNnUX9iKvTbJYvBVb q/jTSFARQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1ghteQ-0008Dc-Il; Fri, 11 Jan 2019 10:02:55 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5C00F201267E1; Fri, 11 Jan 2019 11:02:53 +0100 (CET) Date: Fri, 11 Jan 2019 11:02:53 +0100 From: Peter Zijlstra To: Esme Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , JJiri Olsa , Namhyung Kim , "linux-kernel@vger.kernel.org" Subject: Re: PROBLEM: syzkaller found / reduced C repro for non-fatal unchecked MSR access error Message-ID: <20190111100253.GO30894@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 10, 2019 at 11:21:16PM +0000, Esme wrote: > Attached is a fairly small C repro I did not see any references to > this possible flaw (unchecked MSR access) in relation to > __NR_perf_event_open > > Attached is the config directly extracted from proc. This is the call > stack in relation to the MSR access error (5.0.0-rc1+), I get a very > similar stack running this test case on a stock Ubuntu > "4.18.0-11-generic" (pasted after this one). > -- Esme > > [ 70.228744] unchecked MSR access error: WRMSR to 0xc0010000 (tried to write 0x0000020000130076) at rIP: 0xffffffff812dde28 (native_write_msr+0x8/0x30) That's K7_EVNTSEL0. What kind of hardware are you running this on?