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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 A17A9C433E1 for ; Wed, 8 Jul 2020 20:25:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 818FE20708 for ; Wed, 8 Jul 2020 20:25:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594239911; bh=D7k3xvbEWY4or+QblHb+6CiLuYXwy2HOGXpMEAVtPcQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZvaJrzW0KZmU6X+iXtftmY21xEI3GTlmM/vprnfp79uw8YoCsWnBSBYaF9oqBk3Bu HhU272422tEXX6ismMwPHnHiajPpQoECdhfrfPhnBjM5obgxUgg6Krk4EwZfQylCEl zEMLKQ7eU5qJOqVPl5d6NA/h6EfOT5DaEP0K1x8A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726228AbgGHUZK (ORCPT ); Wed, 8 Jul 2020 16:25:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:37062 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbgGHUZJ (ORCPT ); Wed, 8 Jul 2020 16:25:09 -0400 Received: from sol.localdomain (c-107-3-166-239.hsd1.ca.comcast.net [107.3.166.239]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 24DD3206DF; Wed, 8 Jul 2020 20:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594239909; bh=D7k3xvbEWY4or+QblHb+6CiLuYXwy2HOGXpMEAVtPcQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gmSbuJXrs6tj7XwmAZC5jPwyChbKk72Zpot4gH4a/O0GulkFwT505sKPfaTeV5Ds4 ZafoKJFk9+4hL3TYxcoC6T2O7T7kSTQT2u4WHOkiNJ0aXlBvWzajzFhnK9s9r8RwH3 oAXrxeG6aoCIbSAWd61N96W04rPc8MFJE+wI/sds= Date: Wed, 8 Jul 2020 13:25:07 -0700 From: Eric Biggers To: Casey Schaufler Cc: syzbot , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: kernel panic: smack: Failed to initialize cipso DOI. Message-ID: <20200708202507.GA35321@sol.localdomain> References: <000000000000db448f05a212beea@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000db448f05a212beea@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Casey, On Mon, Mar 30, 2020 at 06:51:18AM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 1b649e0b Merge git://git.kernel.org/pub/scm/linux/kernel/g.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14957099e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4ac76c43beddbd9 > dashboard link: https://syzkaller.appspot.com/bug?extid=89731ccb6fec15ce1c22 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1202c375e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1390bb03e00000 > > The bug was bisected to: > > commit a9d2d53a788a9c5bc8a7d1b4ea7857b68e221357 > Author: Ken Cox > Date: Tue Nov 15 19:00:37 2016 +0000 > > ixgbe: test for trust in macvlan adjustments for VF > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13cb06f3e00000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=102b06f3e00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=17cb06f3e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+89731ccb6fec15ce1c22@syzkaller.appspotmail.com > Fixes: a9d2d53a788a ("ixgbe: test for trust in macvlan adjustments for VF") > > RSP: 002b:00007ffebd499a38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007ffebd499a40 RCX: 00000000004404e9 > RDX: 0000000000000014 RSI: 0000000020000040 RDI: 0000000000000003 > RBP: 0000000000000004 R08: 0000000000000001 R09: 00007ffebd490031 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401dd0 > R13: 0000000000401e60 R14: 0000000000000000 R15: 0000000000000000 > Kernel panic - not syncing: smack: Failed to initialize cipso DOI. > CPU: 1 PID: 7197 Comm: syz-executor480 Not tainted 5.6.0-rc7-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1e9/0x30e lib/dump_stack.c:118 > panic+0x264/0x7a0 kernel/panic.c:221 > smk_cipso_doi+0x4d8/0x4e0 security/smack/smackfs.c:698 > smk_write_doi+0x123/0x190 security/smack/smackfs.c:1595 > __vfs_write+0xa7/0x710 fs/read_write.c:494 > vfs_write+0x271/0x570 fs/read_write.c:558 > ksys_write+0x115/0x220 fs/read_write.c:611 > do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4404e9 > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffebd499a38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007ffebd499a40 RCX: 00000000004404e9 > RDX: 0000000000000014 RSI: 0000000020000040 RDI: 0000000000000003 > RBP: 0000000000000004 R08: 0000000000000001 R09: 00007ffebd490031 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401dd0 > R13: 0000000000401e60 R14: 0000000000000000 R15: 0000000000000000 > Kernel Offset: disabled > Rebooting in 86400 seconds.. > This means that writing to /smack/doi will panic the kernel if kmalloc fails. Why doesn't it handle errors? Is this really an unrecoverable situation? - Eric