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=-16.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL 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 CBE33C10DCE for ; Sun, 8 Mar 2020 17:21:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9464220828 for ; Sun, 8 Mar 2020 17:21:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="RO5mJqse" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726382AbgCHRVJ (ORCPT ); Sun, 8 Mar 2020 13:21:09 -0400 Received: from mail-ot1-f67.google.com ([209.85.210.67]:45694 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726322AbgCHRVJ (ORCPT ); Sun, 8 Mar 2020 13:21:09 -0400 Received: by mail-ot1-f67.google.com with SMTP id f21so7273600otp.12 for ; Sun, 08 Mar 2020 10:21:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PtEA2mm9l96k+awFlKZr4TJ6AG/v1NHyD+CFP5x3VFo=; b=RO5mJqseeWny+mX27K2lObhmY6I9DyzMDNKtt5MNZhWmD7Zb2rB6mqSS0zdoWAY+/H 0mMp5KoxajOn1PqQxzaKCRpYT3JM/bgzhvyGg2PbYEqPFfBYIBWmBzTrTwj5rjoMVCnY /5rgQVAYTyE5zFpliUAACSusk4VqRQ3qW521OgyD8QtUvVUUdPBkcngTAHCNQmUxHEtG UT8OYUmsaBcZdufjl0ASi5XOCy9PtAS4gQ7IdJn3T7enLeJFA26vpwVOk0q7uPtxrL/Z ESPszquBVoN5feDMYDraRkd5DdhasbUp35lz4gJb4t203Hn/GHjax8/2GUcCghLtwntQ LSoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PtEA2mm9l96k+awFlKZr4TJ6AG/v1NHyD+CFP5x3VFo=; b=WwhI9jflhGJ9e52cxUe0m3kUIV6K0ZW3eUKptFsWYDgHlV7mFceqUhPLJXGD+lxFWU I2vWlvYf3vZWgm7bbTcEa+CwbPwchhcSOT+/upGgUgoKhsisBnaPRXt5pYMJ2CBFfUJf 4hMnJgX/t79YzAhU2/oF7wl1qdpo2s2CiBS7xDAxuj/z1pjy/71O2M0UyXfqmdN5/SVZ ae25CZUDOG4tLsN01eMnfcqmCYS5k5bLBuIsG6vYP1qf+fD/QvBP5DteqWYmgj5pwXEH rLRypc6W/UAaE2EYS+kdPk00nDxBJOoHhpgZeaLgfvHYu9Iwt1vaTkOOjcAbqshXDQoI MeRA== X-Gm-Message-State: ANhLgQ0kf1Q+Slf1Lddxt128ze0BjWeMYjSFfsuX0gcdu0WJlatIay28 oteBcnyhG0z8xVulEqzPko6hL7Xyp/xKfEdNjvaLmg== X-Google-Smtp-Source: ADFU+vtF5TJlIqrVcenBMU6JyY5M1kfMbKiy8HlmWV4Ir0C0GIPoIDpylFMIwcKl0vlvlXiADHlQtx1402OgMdb55cE= X-Received: by 2002:a05:6830:1d6e:: with SMTP id l14mr10073990oti.32.1583688067980; Sun, 08 Mar 2020 10:21:07 -0700 (PDT) MIME-Version: 1.0 References: <000000000000ff323f05a053100c@google.com> In-Reply-To: <000000000000ff323f05a053100c@google.com> From: Jann Horn Date: Sun, 8 Mar 2020 18:20:41 +0100 Message-ID: Subject: Re: general protection fault in syscall_return_slowpath To: syzbot Cc: Borislav Petkov , "H . Peter Anvin" , kernel list , Andy Lutomirski , Ingo Molnar , syzkaller-bugs , Thomas Gleixner , "the arch/x86 maintainers" Content-Type: multipart/mixed; boundary="000000000000ba975805a05b1c90" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --000000000000ba975805a05b1c90 Content-Type: text/plain; charset="UTF-8" On Sun, Mar 8, 2020 at 5:40 PM syzbot wrote: > syzbot found the following crash on: > > HEAD commit: 63623fd4 Merge tag 'for-linus' of git://git.kernel.org/pub.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=16cfeac3e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5d2e033af114153f > dashboard link: https://syzkaller.appspot.com/bug?extid=cd66e43794b178bb5cd6 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a42329e00000 [...] > general protection fault, probably for non-canonical address 0x1ffffffff1255a6b: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 8742 Comm: syz-executor.2 Not tainted 5.6.0-rc3-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:arch_local_irq_disable arch/x86/include/asm/paravirt.h:757 [inline] > RIP: 0010:syscall_return_slowpath+0xeb/0x4a0 arch/x86/entry/common.c:277 > Code: 00 10 0f 85 de 00 00 00 e8 b2 a3 76 00 48 c7 c0 58 d3 2a 89 48 c1 e8 03 80 3c 18 00 74 0c 48 c7 c7 58 d3 2a 89 e8 05 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > RSP: 0018:ffffc900020a7ed0 EFLAGS: 00010246 > RAX: 1ffffffff1255a6b RBX: dffffc0000000000 RCX: ffff88808c512380 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffffc900020a7f10 R08: ffffffff810075bb R09: fffffbfff14d9182 > R10: fffffbfff14d9182 R11: 0000000000000000 R12: 1ffff110118a2470 > R13: 0000000000004000 R14: ffff88808c512380 R15: ffff88808c512380 > FS: 000000000154f940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000076c000 CR3: 00000000a6b05000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Let's see if we can get syzkaller to tell us which fbcon implementation it's hitting... #syz test: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux.git 63623fd44972d1ed2bfb6e0fb631dfcf547fd1e7 --000000000000ba975805a05b1c90 Content-Type: text/x-patch; charset="US-ASCII"; name="0001-FOR-TESTING-ONLY-tell-us-which-fbcon-implementation-.patch" Content-Disposition: attachment; filename="0001-FOR-TESTING-ONLY-tell-us-which-fbcon-implementation-.patch" Content-Transfer-Encoding: base64 Content-ID: X-Attachment-Id: f_k7jayolu0 RnJvbSA4NDQyMTQ0ZmU1ODJhYjM4OTg1Mzc4Y2YyMWNhODhkZTE1OTRiNWRmIE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBKYW5uIEhvcm4gPGphbm5oQGdvb2dsZS5jb20+CkRhdGU6IFN1 biwgOCBNYXIgMjAyMCAxODoxNToxMSArMDEwMApTdWJqZWN0OiBbUEFUQ0hdIEZPUiBURVNUSU5H IE9OTFk6IHRlbGwgdXMgd2hpY2ggZmJjb24gaW1wbGVtZW50YXRpb24gaXMgdXNlZAoKLS0tCiBk cml2ZXJzL3R0eS92dC92dC5jIHwgMTAgKysrKysrKystLQogMSBmaWxlIGNoYW5nZWQsIDggaW5z ZXJ0aW9ucygrKSwgMiBkZWxldGlvbnMoLSkKCmRpZmYgLS1naXQgYS9kcml2ZXJzL3R0eS92dC92 dC5jIGIvZHJpdmVycy90dHkvdnQvdnQuYwppbmRleCAwY2ZiYjcxODJiNWEuLmIzZGQ0NDgwMjIw OCAxMDA2NDQKLS0tIGEvZHJpdmVycy90dHkvdnQvdnQuYworKysgYi9kcml2ZXJzL3R0eS92dC92 dC5jCkBAIC00NTkwLDcgKzQ1OTAsNyBAQCBzdGF0aWMgaW50IGNvbl9mb250X2NvcHkoc3RydWN0 IHZjX2RhdGEgKnZjLCBzdHJ1Y3QgY29uc29sZV9mb250X29wICpvcCkKIHsKIAlpbnQgY29uID0g b3AtPmhlaWdodDsKIAlpbnQgcmM7Ci0KKwlzdGF0aWMgdm9pZCAqTEFTVDsKIAogCWNvbnNvbGVf bG9jaygpOwogCWlmICh2Yy0+dmNfbW9kZSAhPSBLRF9URVhUKQpAQCAtNDYwMSw4ICs0NjAxLDE0 IEBAIHN0YXRpYyBpbnQgY29uX2ZvbnRfY29weShzdHJ1Y3QgdmNfZGF0YSAqdmMsIHN0cnVjdCBj b25zb2xlX2ZvbnRfb3AgKm9wKQogCQlyYyA9IC1FTk9UVFk7CiAJZWxzZSBpZiAoY29uID09IHZj LT52Y19udW0pCS8qIG5vdGhpbmcgdG8gZG8gKi8KIAkJcmMgPSAwOwotCWVsc2UKKwllbHNlIHsK KwkJaWYgKExBU1QgIT0gdmMtPnZjX3N3KSB7CisJCQlwcl93YXJuKCJjb25fZm9udF9jb3B5KCk6 IHZjX3N3PSVwUywgdmNfc3ctPmNvbl9mb250X2NvcHk9JXBTXG4iLAorCQkJCXZjLT52Y19zdywg dmMtPnZjX3N3LT5jb25fZm9udF9jb3B5KTsKKwkJCUxBU1QgPSB2Yy0+dmNfc3c7CisJCX0KIAkJ cmMgPSB2Yy0+dmNfc3ctPmNvbl9mb250X2NvcHkodmMsIGNvbik7CisJfQogCWNvbnNvbGVfdW5s b2NrKCk7CiAJcmV0dXJuIHJjOwogfQoKYmFzZS1jb21taXQ6IDYzNjIzZmQ0NDk3MmQxZWQyYmZi NmUwZmI2MzFkZmNmNTQ3ZmQxZTcKLS0gCjIuMjUuMS40ODEuZ2ZiY2UwZWI4MDEtZ29vZwoK --000000000000ba975805a05b1c90--