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=-0.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 E634AC4321D for ; Tue, 21 Aug 2018 21:28:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9891A213A2 for ; Tue, 21 Aug 2018 21:28:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9891A213A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727171AbeHVAty (ORCPT ); Tue, 21 Aug 2018 20:49:54 -0400 Received: from mail-it0-f71.google.com ([209.85.214.71]:38381 "EHLO mail-it0-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726628AbeHVAtx (ORCPT ); Tue, 21 Aug 2018 20:49:53 -0400 Received: by mail-it0-f71.google.com with SMTP id h5-v6so191151itb.3 for ; Tue, 21 Aug 2018 14:28:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=gJakVlmp3jyIfu+2HIKOZVclIV3p6qdYW4qBjCPA8HI=; b=BQbBY2hRL4Fi3yifaYEkmrbwOVRK5Jkw/IcUgtnqWGTRE47o++6+5+qKPCPJEktkai YroIKPQoJHcTa6ZpTn/QxyvzNbuAHczgjunsqS2aUBgW8q6xzUHVPJ9JUcrhoGQKjUFI MqAxFf0uGpa9ll34ZYcFGh4kzuf4hPj4mc4SiYT9GjUmZxEQEHcyoUbW6mpufcFew1tJ uKH+Nk4QgLGZO+Tnq2PIbx130Z7JbOCOzr+Q1yMH/QvQdYWu8eEnh/98nPqQobphjJnd MyWfBW4gxlUm2MO2VD3cgOI+Px9f9wSLpaOXk70nkZxX1RxrXC0aXi080C8SoHiMKfrK Si6A== X-Gm-Message-State: AOUpUlGyrol1HHZac1MHeVpktmHQ5KlPEItRTLx1p0/so7Q6VuTIFLe2 S6wsPn9PleWLcI5jNglf6q26YI0hyoQhf+SO3WRsgORATay+ X-Google-Smtp-Source: AA+uWPxcrul/VOUvDckAUB+GHvrkWpCtG+9PZ2NJuEzOh+hLu6CB5prG1ENd+3MQ4mKIc0oVjrgBn1Y6Ves4+2pEhNAbTOYSTUjy MIME-Version: 1.0 X-Received: by 2002:a6b:9fc1:: with SMTP id i184-v6mr23346752ioe.75.1534886883000; Tue, 21 Aug 2018 14:28:03 -0700 (PDT) Date: Tue, 21 Aug 2018 14:28:02 -0700 In-Reply-To: <00000000000035c2ed057315bf85@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000006e87360573f8b328@google.com> Subject: Re: general protection fault in finish_task_switch (2) From: syzbot To: dvhart@infradead.org, hpa@zytor.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, pbonzini@redhat.com, peterz@infradead.org, rkrcmar@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following crash on: HEAD commit: 778a33959a8a Merge tag 'please-pull-noboot' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14a5385a400000 kernel config: https://syzkaller.appspot.com/x/.config?x=214e4990bd49329f dashboard link: https://syzkaller.appspot.com/bug?extid=1f56df64bfb3c29dde6f compiler: gcc (GCC) 8.0.1 20180413 (experimental) userspace arch: i386 syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=13ffa561400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10023961400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+1f56df64bfb3c29dde6f@syzkaller.appspotmail.com random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN CPU: 0 PID: 4489 Comm: syz-executor233 Not tainted 4.18.0+ #103 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__fire_sched_in_preempt_notifiers kernel/sched/core.c:2481 [inline] RIP: 0010:fire_sched_in_preempt_notifiers kernel/sched/core.c:2487 [inline] RIP: 0010:finish_task_switch+0x538/0x870 kernel/sched/core.c:2679 Code: 89 e1 48 c1 e9 03 42 80 3c 39 00 0f 85 ab 01 00 00 4d 8b 24 24 4d 85 e4 0f 84 e3 fc ff ff 49 8d 7c 24 10 48 89 f9 48 c1 e9 03 <42> 80 3c 39 00 74 a5 e8 8c a5 67 00 eb 9e 80 3d 8b c3 32 07 00 0f RSP: 0018:ffff8801ac0ff058 EFLAGS: 00010a06 RAX: 0000000000000000 RBX: ffff8801db02cc40 RCX: 1bd5a00000000022 RDX: 0000000000000000 RSI: ffffffff810ed162 RDI: dead000000000110 RBP: ffff8801ac0ff140 R08: ffff8801acb8c300 R09: ffffed003b221b6c R10: ffffed003b221b6c R11: ffff8801d910db67 R12: dead000000000100 R13: ffff8801ca5e0040 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801db000000(0063) knlGS:00000000f7f07b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00007f1304e0b000 CR3: 00000001acab3000 CR4: 00000000001426f0 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x884/0x1df0 kernel/sched/core.c:3471 schedule+0xfb/0x450 kernel/sched/core.c:3515 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x3f9/0x840 kernel/futex.c:2530 futex_wait+0x45b/0xa20 kernel/futex.c:2645 do_futex+0x336/0x27d0 kernel/futex.c:3527 __do_compat_sys_futex kernel/futex_compat.c:201 [inline] __se_compat_sys_futex kernel/futex_compat.c:175 [inline] __ia32_compat_sys_futex+0x3d9/0x5f0 kernel/futex_compat.c:175 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f0bca9 Code: 55 08 8b 88 64 cd ff ff 8b 98 68 cd ff ff 89 c8 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 1c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f7f071ec EFLAGS: 00000296 ORIG_RAX: 00000000000000f0 RAX: ffffffffffffffda RBX: 00000000080fb008 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00000000c080aebe R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace a4bb2f1beb6735f0 ]--- RIP: 0010:__fire_sched_in_preempt_notifiers kernel/sched/core.c:2481 [inline] RIP: 0010:fire_sched_in_preempt_notifiers kernel/sched/core.c:2487 [inline] RIP: 0010:finish_task_switch+0x538/0x870 kernel/sched/core.c:2679 Code: 89 e1 48 c1 e9 03 42 80 3c 39 00 0f 85 ab 01 00 00 4d 8b 24 24 4d 85 e4 0f 84 e3 fc ff ff 49 8d 7c 24 10 48 89 f9 48 c1 e9 03 <42> 80 3c 39 00 74 a5 e8 8c a5 67 00 eb 9e 80 3d 8b c3 32 07 00 0f RSP: 0018:ffff8801ac0ff058 EFLAGS: 00010a06 RAX: 0000000000000000 RBX: ffff8801db02cc40 RCX: 1bd5a00000000022 RDX: 0000000000000000 RSI: ffffffff810ed162 RDI: dead000000000110 RBP: ffff8801ac0ff140 R08: ffff8801acb8c300 R09: ffffed003b221b6c R10: ffffed003b221b6c R11: ffff8801d910db67 R12: dead000000000100 R13: ffff8801ca5e0040 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801db000000(0063) knlGS:00000000f7f07b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00007f1304e0b000 CR3: 00000001acab3000 CR4: 00000000001426f0