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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 31057C34031 for ; Tue, 18 Feb 2020 21:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F2D124125 for ; Tue, 18 Feb 2020 21:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726734AbgBRVND (ORCPT ); Tue, 18 Feb 2020 16:13:03 -0500 Received: from mga01.intel.com ([192.55.52.88]:12302 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726339AbgBRVND (ORCPT ); Tue, 18 Feb 2020 16:13:03 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Feb 2020 13:13:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,457,1574150400"; d="scan'208";a="348765756" Received: from unknown (HELO localhost) ([10.252.27.59]) by fmsmga001.fm.intel.com with ESMTP; 18 Feb 2020 13:13:00 -0800 Date: Tue, 18 Feb 2020 23:12:59 +0200 From: Jarkko Sakkinen To: dhowells@redhat.com Cc: jmorris@namei.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, serge@hallyn.com Subject: Re: kernel BUG at lib/assoc_array.c:LINE! Message-ID: <20200218211259.GA19673@linux.intel.com> References: <000000000000f4bf93059db8b081@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000f4bf93059db8b081@google.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Mon, Feb 03, 2020 at 08:44:11PM -0800, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 46d6b7be Merge git://git.kernel.org/pub/scm/linux/kernel/g.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11383a79e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6dda7ccc1e75a63f > dashboard link: https://syzkaller.appspot.com/bug?extid=23e14950fa7550d86091 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > > 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+23e14950fa7550d86091@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > kernel BUG at lib/assoc_array.c:652! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 2778 Comm: kworker/0:37 Not tainted 5.5.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: afs afs_manage_cell > RIP: 0010:assoc_array_insert_into_terminal_node lib/assoc_array.c:652 [inline] > RIP: 0010:assoc_array_insert+0x2baa/0x2bd0 lib/assoc_array.c:1001 > Code: 0f 0b e8 a9 64 d4 fd 0f 0b e8 a2 64 d4 fd 0f 0b e8 9b 64 d4 fd 0f 0b e8 94 64 d4 fd 0f 0b e8 8d 64 d4 fd 0f 0b e8 86 64 d4 fd <0f> 0b e8 7f 64 d4 fd 0f 0b e8 78 64 d4 fd 0f 0b e8 71 64 d4 fd 0f > RSP: 0018:ffffc900087ff810 EFLAGS: 00010293 > RAX: ffffffff83a25a7a RBX: 1ffff11012d568af RCX: ffff88809f34a580 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffffc900087ff920 R08: ffffffff83a249fd R09: ffffffff83538f4f > R10: ffff88809f34a580 R11: 0000000000000004 R12: ffff888096ab4588 > R13: ffff888096ab4500 R14: ffff888096ab4578 R15: dffffc0000000000 > FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000738000 CR3: 0000000054a3b000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __key_link_begin+0xfe/0x230 security/keys/keyring.c:1316 > construct_alloc_key security/keys/request_key.c:404 [inline] > construct_key_and_link security/keys/request_key.c:499 [inline] > request_key_and_link+0x9b6/0x1680 security/keys/request_key.c:637 > request_key_tag+0x53/0x190 security/keys/request_key.c:701 > dns_query+0x266/0x6c0 net/dns_resolver/dns_query.c:128 > afs_dns_query+0xdd/0x320 fs/afs/addr_list.c:249 > afs_update_cell fs/afs/cell.c:391 [inline] > afs_manage_cell+0xda2/0x1500 fs/afs/cell.c:693 > process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264 > worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410 > kthread+0x332/0x350 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > Modules linked in: > ---[ end trace 9dabb2deade74362 ]--- > RIP: 0010:assoc_array_insert_into_terminal_node lib/assoc_array.c:652 [inline] > RIP: 0010:assoc_array_insert+0x2baa/0x2bd0 lib/assoc_array.c:1001 > Code: 0f 0b e8 a9 64 d4 fd 0f 0b e8 a2 64 d4 fd 0f 0b e8 9b 64 d4 fd 0f 0b e8 94 64 d4 fd 0f 0b e8 8d 64 d4 fd 0f 0b e8 86 64 d4 fd <0f> 0b e8 7f 64 d4 fd 0f 0b e8 78 64 d4 fd 0f 0b e8 71 64 d4 fd 0f > RSP: 0018:ffffc900087ff810 EFLAGS: 00010293 > RAX: ffffffff83a25a7a RBX: 1ffff11012d568af RCX: ffff88809f34a580 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffffc900087ff920 R08: ffffffff83a249fd R09: ffffffff83538f4f > R10: ffff88809f34a580 R11: 0000000000000004 R12: ffff888096ab4588 > R13: ffff888096ab4500 R14: ffff888096ab4578 R15: dffffc0000000000 > FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000013e4978 CR3: 000000008adb2000 CR4: 00000000001406f0 > 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#status for how to communicate with syzbot. The arguments for request_key_and_link() are fairly constrained: type == &key_type_dns_resolver description == "afsdb:" domain_tag == net->key_domain callout_info == "srv=1" callout_len == 5 aux == NULL dest_keyring == NULL flags == KEY_ALLOC_IN_QUOTA (manually resolved) The only obvious moving part I see is the key type implementatio i.e. net/dns_resolver/dns_key.c. /Jarkko