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=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, 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 69A08C433DF for ; Mon, 24 Aug 2020 00:01:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F4F020720 for ; Mon, 24 Aug 2020 00:01:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="eboFhLVZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727125AbgHXABX (ORCPT ); Sun, 23 Aug 2020 20:01:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726663AbgHXABW (ORCPT ); Sun, 23 Aug 2020 20:01:22 -0400 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E07BFC061573 for ; Sun, 23 Aug 2020 17:01:21 -0700 (PDT) Received: by mail-lj1-x243.google.com with SMTP id h19so7612922ljg.13 for ; Sun, 23 Aug 2020 17:01:21 -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=uz0KdTCCniS0o52VVCzrGMXm4hqB7aop4qmoNp1sJhQ=; b=eboFhLVZvOjSay5QbGG5OMBGuElovYgu0MzGpwTxXyrrkKb2jIGcJ6ThE0D+wKzlwo QXGqfHA1ecrKr2Rth+9zZR69ma2MaQhOLESBMYXCqxwpi7JNthndQdcbsRYgJsvjXjMT Mdx1dm621TxyGfzyULLeYYZcAHgNXn8o65guxsO1UXqz9XPL0A3whmahLJRTXR2/J/cd 3GXpeWM/4cWoLW3VQG29PgFdMWktb9JYiborQyJQOXvkzq6sPv3BV8XF5nLh8mznnjIv uBv4FeJXHFBYolvo91BXYJGOEok+2m/ui8yU/bj48a07997jfsS+wI4FxAS1NoMGoAej ywsw== 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=uz0KdTCCniS0o52VVCzrGMXm4hqB7aop4qmoNp1sJhQ=; b=Rz9mSg03vBP0MmHWGh3ksMxdJlB9AfCmDwNiLeIG4x9jWdV/5bu5Rvi/UcRyzpvB78 M4BcewauU6jgfFIdVuGV91GrKuTZGSGpDpFXY9U/wzC08JW1GfDD18zm/K89VESBpWQ+ W0A1sCr9RngLAdCUXLdm/tCWesvICA4DcTlSggayEwC/q5kJWQ9Di1KlTS63VHdnf0cg VBx+lbiUi6lqSOo3XgzVc/SQ4r3yxxR/vQ66YOyAMzbc0/rlH9y0zFq5Y1DjANkxNXP/ almyd3mvlPYSpMfGnGXHYkSw7sRwVKlBXDpxNGZTMMRKX7/b2CF5RBUXKn2XA7YNhxwi 31QA== X-Gm-Message-State: AOAM532hHYSl8QraYEexDa2n4Pfqft047MzgcgPVyQn2uqvgnx1SFEIB oh5bU9wxmLAP5TX2uBFVylvtyEBMh7owcyC9rp5mDQ== X-Google-Smtp-Source: ABdhPJyY8ulx9DDSt4amXHtxe2lsCKj6n2Hz7qmxNAQ/GKOJnh5f1zcZ4+MPdSVtXAbjLvDzQKoJGXselq9jMnwDLxE= X-Received: by 2002:a2e:9d8e:: with SMTP id c14mr1495978ljj.332.1598227279885; Sun, 23 Aug 2020 17:01:19 -0700 (PDT) MIME-Version: 1.0 References: <000000000000067ab705ac501e5f@google.com> <41cb418a-572e-80d7-214a-ad7131fdc0f2@infradead.org> In-Reply-To: <41cb418a-572e-80d7-214a-ad7131fdc0f2@infradead.org> From: Shakeel Butt Date: Sun, 23 Aug 2020 17:01:08 -0700 Message-ID: Subject: Re: kernel BUG at kernel/fork.c:LINE! To: Randy Dunlap Cc: syzbot , Andrew Morton , Christian Brauner , christian@kellner.me, Kees Cook , LKML , luto@amacapital.net, Ingo Molnar , syzkaller-bugs , Thomas Gleixner , wad@chromium.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 23, 2020 at 10:34 AM Randy Dunlap wrote: > > On 8/7/20 2:16 PM, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: fffe3ae0 Merge tag 'for-linus-hmm' of git://git.kernel.org.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=1194d90a900000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=18bb86f2e4ebfda2 > > dashboard link: https://syzkaller.appspot.com/bug?extid=3776ecd80aac504e6085 > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+3776ecd80aac504e6085@syzkaller.appspotmail.com > > Is this fixed by > > commit 991e7673859ed41e7ba83c8c4e57afe8cfebe314 > Author: Shakeel Butt > Date: Thu Aug 6 23:21:37 2020 -0700 > > mm: memcontrol: account kernel stack per node > > > since the BUG_ON() at line 390 is removed by this patch. > It's not really removed. The BUG_ON() has been moved to line 402. So, this issue might still occur. > > > ------------[ cut here ]------------ > > kernel BUG at kernel/fork.c:390! > > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > > CPU: 0 PID: 5239 Comm: syz-executor.1 Not tainted 5.8.0-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > RIP: 0010:account_kernel_stack+0x297/0x320 kernel/fork.c:390 > > Code: 89 e2 be 23 00 00 00 48 89 ef c1 e2 05 e8 81 9e 75 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f e9 ae c9 2f 00 e8 a9 c9 2f 00 <0f> 0b e8 f2 50 6f 00 e9 d2 fd ff ff e8 98 c9 2f 00 48 c7 c6 20 24 > > RSP: 0018:ffffc90015e4f850 EFLAGS: 00010216 > > RAX: 00000000000001f4 RBX: 0000000000000000 RCX: ffffc90017983000 > > RDX: 0000000000040000 RSI: ffffffff81445327 RDI: 0000000000000005 > > RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8880a2ef9663 > > R10: 0000000000000008 R11: 0000000000000000 R12: ffffffffffffffff > > R13: ffff8880001b2280 R14: ffff88809e4fa840 R15: 0000000000000000 > > FS: 00007f7f035e5700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000001b2fd30000 CR3: 000000009b747000 CR4: 00000000001506f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > release_task_stack kernel/fork.c:447 [inline] > > put_task_stack+0xc4/0x230 kernel/fork.c:459 > > finish_task_switch+0x52a/0x750 kernel/sched/core.c:3649 > > context_switch kernel/sched/core.c:3781 [inline] > > __schedule+0x8ed/0x21e0 kernel/sched/core.c:4527 > > schedule+0xd0/0x2a0 kernel/sched/core.c:4602 > > freezable_schedule include/linux/freezer.h:172 [inline] > > futex_wait_queue_me+0x2a7/0x570 kernel/futex.c:2588 > > futex_wait+0x1df/0x560 kernel/futex.c:2690 > > do_futex+0x15b/0x1a60 kernel/futex.c:3749 > > __do_sys_futex kernel/futex.c:3810 [inline] > > __se_sys_futex kernel/futex.c:3778 [inline] > > __x64_sys_futex+0x378/0x4e0 kernel/futex.c:3778 > > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > RIP: 0033:0x45ccd9 > > Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > > RSP: 002b:00007f7f035e4cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > > RAX: ffffffffffffffda RBX: 000000000078bfa8 RCX: 000000000045ccd9 > > RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bfa8 > > RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac > > R13: 00007fff896cb67f R14: 00007f7f035e59c0 R15: 000000000078bfac > > Modules linked in: > > ---[ end trace ff14b6c5822b8142 ]--- > > RIP: 0010:account_kernel_stack+0x297/0x320 kernel/fork.c:390 > > Code: 89 e2 be 23 00 00 00 48 89 ef c1 e2 05 e8 81 9e 75 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f e9 ae c9 2f 00 e8 a9 c9 2f 00 <0f> 0b e8 f2 50 6f 00 e9 d2 fd ff ff e8 98 c9 2f 00 48 c7 c6 20 24 > > RSP: 0018:ffffc90015e4f850 EFLAGS: 00010216 > > RAX: 00000000000001f4 RBX: 0000000000000000 RCX: ffffc90017983000 > > RDX: 0000000000040000 RSI: ffffffff81445327 RDI: 0000000000000005 > > RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8880a2ef9663 > > R10: 0000000000000008 R11: 0000000000000000 R12: ffffffffffffffff > > R13: ffff8880001b2280 R14: ffff88809e4fa840 R15: 0000000000000000 > > FS: 00007f7f035e5700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000001b2fd30000 CR3: 000000009b747000 CR4: 00000000001506f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > > > > --- > > This report is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkaller@googlegroups.com. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > > > > -- > ~Randy >