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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2B03C07E9D for ; Mon, 26 Sep 2022 14:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235436AbiIZO5T convert rfc822-to-8bit (ORCPT ); Mon, 26 Sep 2022 10:57:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235064AbiIZO4j (ORCPT ); Mon, 26 Sep 2022 10:56:39 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C142857205; Mon, 26 Sep 2022 06:27:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 23BE4CE115A; Mon, 26 Sep 2022 13:27:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3A53C433D6; Mon, 26 Sep 2022 13:27:35 +0000 (UTC) Date: Mon, 26 Sep 2022 09:28:43 -0400 From: Steven Rostedt To: Alexei Starovoitov Cc: Dave Hansen , Linus Torvalds , tech-board@lists.linuxfoundation.org, Song Liu , Kernel Team , jane.chu@oracle.com, Tom Lendacky , X86 ML , brijesh.singh@amd.com, "open list:BPF \(Safe dynamic programs and tools\)" , Daniel Borkmann , Peter Zijlstra , seanjc@google.com, Dave Hansen , syzkaller-bugs , LKML , Alexei Starovoitov , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , John Fastabend , Thomas Gleixner , "Kirill A. Shutemov" Subject: Re: [Tech-board] [syzbot] WARNING in __change_page_attr_set_clr Message-ID: <20220926092843.75a4b751@gandalf.local.home> In-Reply-To: References: <00000000000076f3a305e97e9229@google.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Sun, 25 Sep 2022 14:55:46 -0700 Alexei Starovoitov wrote: > On Sun, Sep 25, 2022 at 9:44 AM Dave Hansen wrote: > > > > On 9/25/22 04:18, syzbot wrote: > > > ------------[ cut here ]------------ > > > CPA refuse W^X violation: 8000000000000163 -> 0000000000000163 range: 0xffffffffa0401000 - 0xffffffffa0401fff PFN 7d8d5 > > > WARNING: CPU: 0 PID: 3607 at arch/x86/mm/pat/set_memory.c:600 verify_rwx arch/x86/mm/pat/set_memory.c:600 [inline] > > > WARNING: CPU: 0 PID: 3607 at arch/x86/mm/pat/set_memory.c:600 __change_page_attr arch/x86/mm/pat/set_memory.c:1569 [inline] > > > WARNING: CPU: 0 PID: 3607 at arch/x86/mm/pat/set_memory.c:600 __change_page_attr_set_clr+0x1f40/0x2020 arch/x86/mm/pat/set_memory.c:1691 > > > Modules linked in: > > > > Yay, one of these that isn't due to wonky 32-bit kernels! > > > > This one looks to be naughty intentionally: > > > > > void *bpf_jit_alloc_exec_page(void) > > > { > > ... > > > /* Keep image as writeable. The alternative is to keep flipping ro/rw > > > * every time new program is attached or detached. > > > */ > > > set_memory_x((long)image, 1); > > > return image; > > > } > > > > For STRICT_KERNEL_RWX kernels, I think we would really rather that this > > code *did* flip ro/rw every time a new BPF program is attached or detached. > > Steven Rostedt noticed that comment around the middle of August > and told you and Peter about it. > Then Peter added a WARN_ONCE in commit > https://lore.kernel.org/all/YwySW3ROc21hN7g9@hirez.programming.kicks-ass.net/ > to explicitly trigger that known issue. > Sure enough the fedora fails to boot on linux-next since then, > because systemd is loading bpf programs that use bpf trampoline. > The boot issue was was reported 3 days ago: > https://lore.kernel.org/bpf/c84cc27c1a5031a003039748c3c099732a718aec.camel@kernel.org/T/#u > Now we're trying to urgently address it with: > https://lore.kernel.org/bpf/20220923211837.3044723-1-song@kernel.org/ > > So instead of pinging us with your w^x concern you've decided > to fail hard in -next to force the issue and > now acting like this is something surprising to you?! > > This is Code of Conduct "worthy" behavior demonstrated Here's the link to the Code of Conduct: https://www.kernel.org/doc/html/latest/process/code-of-conduct.html Which states: Examples of behavior that contributes to creating a positive environment include: - Using welcoming and inclusive language - Being respectful of differing viewpoints and experiences - Gracefully accepting constructive criticism - Focusing on what is best for the community - Showing empathy towards other community members Examples of unacceptable behavior by participants include: - The use of sexualized language or imagery and unwelcome sexual attention or advances - Trolling, insulting/derogatory comments, and personal or political attacks - Public or private harassment - Publishing others’ private information, such as a physical or electronic address, without explicit permission - Other conduct which could reasonably be considered inappropriate in a professional setting I do not see how Dave's response is a violation of any of the above. > by a newly elected member of the Technical Advisory Board. > Please consider resigning. Asking someone to resign is a personal attack, and that can be construed as a violation of the Code of Conduct. > A TAB member should be better than this. > Let's please keep this on a technical level, as there appears to be a fix we all can agree on, and let's move forward on that. Thanks, -- Steve