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=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E316EC47087 for ; Wed, 26 May 2021 00:33:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC31E6142B for ; Wed, 26 May 2021 00:33:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232463AbhEZAe5 (ORCPT ); Tue, 25 May 2021 20:34:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:48340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232290AbhEZAe4 (ORCPT ); Tue, 25 May 2021 20:34:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9D48A61417; Wed, 26 May 2021 00:33:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621989206; bh=HDyj3Lt2w9z4WJtu0hesbCgJr4a66qSh8QOFDKrJ9J4=; h=Subject:To:References:From:Date:In-Reply-To:From; b=Fw0xWHOgUOyrHsTIO7DU5D9aHyHimascPwNN6oTKh4scMils2AJyWsvx7jeM+ss4P pGPNvgzE2d1ms38fwUaLIs4XYa5hQ0csX+Em0NMbY+LVsHe5moaME2cN1Td3ejMtoJ RWW1siysaGxzgppItsnTps2dI6EI/C7tUk361i/UJDTyLkz3A5WgJlgZsfQjCsKOZC AaRXd6RMQekkhPDJXQI1kWnzdlNZVZoDWooIxora1A9CVN0I2kjvVy6MEOL6CakQN4 L6OdLSvGtH5sLMXKSoroY9vObNQSLUTx3kX1vccNvIEhWu7znmpMfdJqkW/3pO6i1F 35vMeimHFG6Qg== Subject: Re: [syzbot] WARNING in ex_handler_fprestore To: syzbot , bp@alien8.de, bp@suse.de, dave.hansen@linux.intel.com, fenghua.yu@intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, tony.luck@intel.com, x86@kernel.org, yu-cheng.yu@intel.com References: <0000000000004c453905c30f8334@google.com> From: Andy Lutomirski Message-ID: Date: Tue, 25 May 2021 17:33:25 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <0000000000004c453905c30f8334@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/24/21 1:51 AM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 45af60e7 Merge tag 'for-5.13-rc2-tag' of git://git.kernel... > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1591e9f7d00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=18fade5827eb74f7 > dashboard link: https://syzkaller.appspot.com/bug?extid=2067e764dbcd10721e2e > compiler: Debian clang version 11.0.1-2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11be6bd1d00000 Hi syz people and x86 people- I entirely believe that this bug is real and that syzbot bisected it correctly, but I'm puzzled by the reproducer. It says: ptrace$setregs(0xd, r0, 0x0, &(0x7f0000000080)) I would really, really expect this to result from PTRACE_SETREGSET or PTRACE_SETFPREGS, but this is PTRACE_SETREGS. Am I missing something really obvious here?