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=-8.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED,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 E9850C43381 for ; Wed, 20 Feb 2019 16:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AC1C02146E for ; Wed, 20 Feb 2019 16:57:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Kxi65kUm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726462AbfBTQ5p (ORCPT ); Wed, 20 Feb 2019 11:57:45 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:37030 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725801AbfBTQ5o (ORCPT ); Wed, 20 Feb 2019 11:57:44 -0500 Received: by mail-it1-f193.google.com with SMTP id z124so17209952itc.2 for ; Wed, 20 Feb 2019 08:57:43 -0800 (PST) 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=AeFUJWAPX0cp3TlR/Bl/I/BN8/f1s/bZd9Fwz0Uko6M=; b=Kxi65kUm9MafI1pEoaykhaba+/3zBLeS32CM2kzf6eo5GPJa0hGV9MY0i51E+pGeM0 tWtEZIrwI0yGcYrBIng+k0Ow36WrbLwsVLgkeOznCbVOTIBFSY0896NkLQ75X6BxVh0T 8kdBQsPQq4Q9YGIKLIPN18hZMbPQxMfYkYzK0SnX/f2axFIcOHPhqi0DlbTiPgqMtavQ /TwqrxagFE4dkRfiOYgXoaktcnPmcL0QbDh5eUV3RnsymqNT4qIZmodHgOv5D1aY4MRt n4C0h82jj0QjWFy8zehPo9el4Jcj6s808j2mIpojj+u+zXWdoB1ceXogdczxPNDonTW7 FchQ== 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=AeFUJWAPX0cp3TlR/Bl/I/BN8/f1s/bZd9Fwz0Uko6M=; b=lDXqyKh/dRBayJ4xP/L+kaVB5vp0BmCkRAg83UBtLN/zTxMFdBbJjAXWxLm4kAiqqe 1SfqxMlUtE4FKwTekxNoNdhOQOOtmYyMfJG5M1LhVYx1Q6aLH6HM4xMmLSLzu1gIKPbz 97KYNQRO516Xkt0ctp/b2y+zWNHUEywyiY+Qsp9uhmUjcIq3Jjc+TGn8BRXn8tSgtI4y 5cv0lRWBJeM+LvbH/dx1fOWnaqcQ6k3LFtdf8FJEWC3Bn4HJ4LlOIhtM7wOm6xT3zjHs 1PUWzcEI+xwAIwma7aMPYJoNzzhHO6XFmhWGbfX0Yn3ZGDu/btQuSV+scvyyAQxSdx1U 2e/g== X-Gm-Message-State: AHQUAubQJY5uJojn2z/DTqlqEqTmw5DFhvrDSUgcY2y8XHpkhe/qdNrW zQeGhIPdJxSLUjfG03NF1AEYwAjN3k2joXftsSZ2lg== X-Google-Smtp-Source: AHgI3IZ6g4dt1xBOPc6PQalN29VM2uFMQGI1jRzXpyfUMIrVSzuVyr1GfpgflBhgzZhTddmbDkbugcrQjH8gWrmj7c4= X-Received: by 2002:a24:7351:: with SMTP id y78mr5948931itb.12.1550681863149; Wed, 20 Feb 2019 08:57:43 -0800 (PST) MIME-Version: 1.0 References: <000000000000739dd40575ac7d07@google.com> In-Reply-To: <000000000000739dd40575ac7d07@google.com> From: Dmitry Vyukov Date: Wed, 20 Feb 2019 17:57:32 +0100 Message-ID: Subject: Re: general protection fault in lockref_get To: syzbot Cc: Andrew Morton , Arnd Bergmann , David Howells , "Eric W. Biederman" , LKML , syzkaller-bugs , Al Viro 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 Wed, Sep 12, 2018 at 3:23 PM syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 7c1b097f27bf Add linux-next specific files for 20180912 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1333df01400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5980033172920ec0 > dashboard link: https://syzkaller.appspot.com/bug?extid=5dc733a19636067b82fd > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+5dc733a19636067b82fd@syzkaller.appspotmail.com > > random: sshd: uninitialized urandom read (32 bytes read) > random: sshd: uninitialized urandom read (32 bytes read) > random: cc1: uninitialized urandom read (8 bytes read) > kasan: CONFIG_KASAN_INLINE enabled > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 5580 Comm: syz-executor0 Not tainted 4.19.0-rc3-next-20180912+ > #72 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:__lock_acquire+0x237/0x4ec0 kernel/locking/lockdep.c:3291 Let's do: #syz dup: BUG: spinlock bad magic in lockref_get Both in the same function and appeared exactly at the same time, but the other one has a reproducer: https://syzkaller.appspot.com/bug?id=59881761edbba4b3f7511eea9fe539c90a87f13c > Code: 28 00 00 00 0f 85 aa 33 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f > 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f > 85 6d 35 00 00 49 81 7d 00 20 90 9e 8a 0f 84 54 ff > RSP: 0018:ffff8801d36ff430 EFLAGS: 00010006 > RAX: dffffc0000000000 RBX: 1ffff1003a6dff03 RCX: 0000000000000000 > RDX: 0000000140000014 RSI: 0000000000000000 RDI: ffffffff89722928 > RBP: ffff8801d36ff7c0 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000a000000a0 R14: ffff8801b9cde100 R15: 0000000000000000 > FS: 0000000000db8940(0000) GS:ffff8801dad00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000482e00 CR3: 00000001b9d4f000 CR4: 00000000001406e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 > lockref_get+0x15/0x50 include/linux/spinlock.h:329 > dget include/linux/dcache.h:322 [inline] > mqueue_get_tree+0x101/0x2e0 ipc/mqueue.c:362 > vfs_get_tree+0x1cb/0x5c0 fs/super.c:1787 > mq_create_mount+0xe3/0x190 ipc/mqueue.c:415 > mq_init_ns+0x15a/0x210 ipc/mqueue.c:1621 > create_ipc_ns ipc/namespace.c:58 [inline] > copy_ipcs+0x3d2/0x580 ipc/namespace.c:84 > create_new_namespaces+0x376/0x900 kernel/nsproxy.c:87 > unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206 > ksys_unshare+0x79c/0x10b0 kernel/fork.c:2535 > __do_sys_unshare kernel/fork.c:2603 [inline] > __se_sys_unshare kernel/fork.c:2601 [inline] > __x64_sys_unshare+0x31/0x40 kernel/fork.c:2601 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x459d87 > Code: 00 00 00 b8 63 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 3d 8a fb ff c3 > 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff > ff 0f 83 1d 8a fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffcccf0eee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459d87 > RDX: 0000000000000000 RSI: 00007ffcccf0eef0 RDI: 0000000008000000 > RBP: 0000000000930b28 R08: 0000000000000000 R09: 0000000000000018 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000010 > R13: 0000000000412cc0 R14: 0000000000000000 R15: 0000000000000000 > Modules linked in: > ---[ end trace 404378fbbfe9896c ]--- > RIP: 0010:__lock_acquire+0x237/0x4ec0 kernel/locking/lockdep.c:3291 > Code: 28 00 00 00 0f 85 aa 33 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f > 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f > 85 6d 35 00 00 49 81 7d 00 20 90 9e 8a 0f 84 54 ff > RSP: 0018:ffff8801d36ff430 EFLAGS: 00010006 > RAX: dffffc0000000000 RBX: 1ffff1003a6dff03 RCX: 0000000000000000 > RDX: 0000000140000014 RSI: 0000000000000000 RDI: ffffffff89722928 > RBP: ffff8801d36ff7c0 R08: 0000000000000001 R09: 0000000000000001 > R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000a000000a0 R14: ffff8801b9cde100 R15: 0000000000000000 > FS: 0000000000db8940(0000) GS:ffff8801dad00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000482e00 CR3: 00000001b9d4f000 CR4: 00000000001406e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000739dd40575ac7d07%40google.com. > For more options, visit https://groups.google.com/d/optout.