From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756008Ab3BTIYE (ORCPT ); Wed, 20 Feb 2013 03:24:04 -0500 Received: from relay.parallels.com ([195.214.232.42]:54966 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863Ab3BTIYB (ORCPT ); Wed, 20 Feb 2013 03:24:01 -0500 Message-ID: <512487FA.9090102@parallels.com> Date: Wed, 20 Feb 2013 12:23:22 +0400 From: Stanislav Kinsbursky User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Dave Jones , Linux Kernel , Andrew Morton Subject: Re: general protection fault in do_msgrcv [3.8] References: <20130219180441.GA27141@redhat.com> In-Reply-To: <20130219180441.GA27141@redhat.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.30.29.37] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 19.02.2013 22:04, Dave Jones пишет: > general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > Modules linked in: can af_rxrpc binfmt_misc scsi_transport_iscsi ax25 ipt_ULOG decnet nfc appletalk x25 rds ipx p8023 psnap p8022 llc irda crc_ccitt atm lockd sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack nf_conntrack ip6table_filter ip6_tables btusb bluetooth snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_pcm edac_core snd_page_alloc snd_timer microcode rfkill usb_debug serio_raw pcspkr snd soundcore vhost_net r8169 mii tun macvtap macvlan kvm_amd kvm > CPU 2 > Pid: 887, comm: trinity-child2 Not tainted 3.8.0+ #57 Gigabyte Technology Co., Ltd. GA-MA78GM-S2H/GA-MA78GM-S2H > RIP: 0010:[] [] do_msgrcv+0x22a/0x670 > RSP: 0018:ffff88011892be88 EFLAGS: 00010297 > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000004000 > RDX: 000000007adea6f6 RSI: 6b6b6b6b6b6b6b6b RDI: ffff8801189ffb60 > RBP: ffff88011892bf68 R08: 0000000000000001 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: ffff8801189ffc10 R14: ffff8801189ffb60 R15: 6b6b6b6b6b6b6b6b > FS: 00007f681e955740(0000) GS:ffff88012f200000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f681e846064 CR3: 000000012553d000 CR4: 00000000000007e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process trinity-child2 (pid: 887, threadinfo ffff88011892a000, task ffff88010bc82490) > Stack: > ffff88011892beb8 ffff88010bc82490 ffff88010bc82490 ffff88010bc82490 > ffff8801186d8000 ffffffff812ad5f0 0000000001aba000 ffffffff81c688c0 > 000000007adea6f6 00000000001fffff 0000400046a9467e 6b6b6b6b6b6b6b6b > Call Trace: > [] ? load_msg+0x180/0x180 > [] ? trace_hardirqs_on_caller+0x115/0x1a0 > [] ? trace_hardirqs_on_thunk+0x3a/0x3f > [] sys_msgrcv+0x15/0x20 > [] system_call_fastpath+0x16/0x1b > Code: 84 14 01 00 00 8b 8d 74 ff ff ff 85 c9 0f 84 52 02 00 00 48 8b 95 60 ff ff ff 48 39 55 80 0f 84 4d 02 00 00 4c 89 bd 78 ff ff ff <4d> 8b 3f 48 ff 45 80 4d 39 ef 75 9a 66 90 48 81 bd 78 ff ff ff > RIP [] do_msgrcv+0x22a/0x670 > RSP > ---[ end trace d3cc044a84b1d828 ]--- > > oopsing instruction is.. > > 0: 4d 8b 3f mov (%r15),%r15 > > Looks like a use-after-free. > > Disassembly of ipc/msg.o shows this happens here.. > > msg = ERR_PTR(-EAGAIN); > tmp = msq->q_messages.next; > 1537: 4d 8b be b0 00 00 00 mov 0xb0(%r14),%r15 > while (tmp != &msq->q_messages) { > 153e: 4d 8d ae b0 00 00 00 lea 0xb0(%r14),%r13 > 1545: 4d 39 ef cmp %r13,%r15 > 1548: 0f 84 5f 03 00 00 je 18ad > 154e: 48 c7 45 80 00 00 00 movq $0x0,-0x80(%rbp) > 1555: 00 > 1556: 48 c7 85 78 ff ff ff movq $0xfffffffffffffff5,-0x88(%rbp) > 155d: f5 ff ff ff > 1561: eb 0d jmp 1570 > 1563: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) > } > } else > break; > msg_counter++; > } > tmp = tmp->next; > 1568: 4d 8b 3f mov (%r15),%r15 > if (ipcperms(ns, &msq->q_perm, S_IRUGO)) > goto out_unlock; > > msg = ERR_PTR(-EAGAIN); > tmp = msq->q_messages.next; > while (tmp != &msq->q_messages) { > > Looks like Stanislav recently changed this code, so problem was likely introduced > in those changes. > Hello. Is it easy to reproduce? Do you use KVM? There is a NULL selinux handler bug fix by Stephen Smalley here: https://lkml.org/lkml/2013/2/6/663 But anyway, this bug fix affects only the case, when MSG_COPY flag is set. And this is not your case, I suppose? > Dave > -- Best regards, Stanislav Kinsbursky