From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tommi Rantala Subject: soft lockup at __skb_recv_datagram() when fuzzing with trinity as root in VM Date: Mon, 11 Feb 2013 21:25:51 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Dave Jones To: netdev@vger.kernel.org Return-path: Received: from mail-vc0-f170.google.com ([209.85.220.170]:41102 "EHLO mail-vc0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759136Ab3BKTZx (ORCPT ); Mon, 11 Feb 2013 14:25:53 -0500 Received: by mail-vc0-f170.google.com with SMTP id p16so4020214vcq.1 for ; Mon, 11 Feb 2013 11:25:52 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: Hello, I am quite easily reproducing this lockup when fuzzing with Trinity as the root user in a virtual machine. It seems to be busy-looping in the do-while loop in __skb_recv_datagram(). [ 83.541011] INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 0, t=26002 jiffies, g=27673, c=27672, q=75) [ 83.541011] INFO: Stall ended before state dump start [ 108.067010] BUG: soft lockup - CPU#0 stuck for 22s! [trinity-child31:2847] [ 108.067010] irq event stamp: 244034822 [ 108.067010] hardirqs last enabled at (244034821): [] _raw_spin_unlock_irqrestore+0x55/0x70 [ 108.067010] hardirqs last disabled at (244034822): [] apic_timer_interrupt+0x6d/0x80 [ 108.067010] softirqs last enabled at (244030010): [] __do_softirq+0x1ca/0x240 [ 108.067010] softirqs last disabled at (244030005): [] call_softirq+0x1c/0x30 [ 108.067010] CPU 0 [ 108.067010] Pid: 2847, comm: trinity-child31 Tainted: G W 3.8.0-rc7+ #73 Bochs Bochs [ 108.067010] RIP: 0010:[] [] _raw_spin_unlock_irqrestore+0x5a/0x70 [ 108.067010] RSP: 0018:ffff88002fb5db38 EFLAGS: 00000286 [ 108.067010] RAX: ffff8800201ec520 RBX: ffffffff810d54fa RCX: 0000000000005220 [ 108.067010] RDX: ffff8800201ec520 RSI: 0000000000000001 RDI: 0000000000000286 [ 108.067010] RBP: ffff88002fb5db48 R08: 0000000000000068 R09: 0000000000000001 [ 108.067010] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff810f5b9d [ 108.067010] R13: ffff88002fb5daa8 R14: 00000019294ba499 R15: 0000000000000086 [ 108.067010] FS: 00007f6aabc57700(0000) GS:ffff88003e000000(0000) knlGS:0000000000000000 [ 108.067010] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 108.067010] CR2: 0000000000000009 CR3: 000000002fb08000 CR4: 00000000000006f0 [ 108.067010] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 108.067010] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 108.067010] Process trinity-child31 (pid: 2847, threadinfo ffff88002fb5c000, task ffff8800201ec520) [ 108.067010] Stack: [ 108.067010] ffff88002fb5dc10 ffff88002fb5dc14 ffff88002fb5dbf8 ffffffff818cc103 [ 108.067010] ffff8800391a7d80 ffff8800201ec520 ffff88002fb5dbb8 7fffffffffffffff [ 108.067010] ffff88002fb5dc54 40001202810d54fa ffff8800201ec520 ffff8800277f87e8 [ 108.067010] Call Trace: [ 108.067010] [] __skb_recv_datagram+0x1a3/0x3b0 [ 108.067010] [] ? csum_partial_copy_fromiovecend+0x220/0x220 [ 108.067010] [] skb_recv_datagram+0x2d/0x30 [ 108.067010] [] ? selinux_syslog+0x70/0x70 [ 108.067010] [] rawv6_recvmsg+0xad/0x240 [ 108.067010] [] sock_common_recvmsg+0x34/0x50 [ 108.067010] [] sock_recvmsg+0xbc/0xf0 [ 108.067010] [] ? kvm_clock_read+0x1f/0x30 [ 108.067010] [] ? sched_clock+0x9/0x10 [ 108.067010] [] sys_recvfrom+0xde/0x150 [ 108.067010] [] ? trace_hardirqs_on+0xd/0x10 [ 108.067010] [] ? _raw_spin_unlock_irq+0x2b/0x40 [ 108.067010] [] ? sysret_check+0x22/0x5d [ 108.067010] [] ? trace_hardirqs_on_caller+0x155/0x1f0 [ 108.067010] [] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 108.067010] [] system_call_fastpath+0x16/0x1b [ 108.067010] Code: ff f6 c7 02 75 1b 48 89 df 57 9d 0f 1f 44 00 00 e8 fc 2d 45 ff eb 19 66 2e 0f 1f 84 00 00 00 00 00 e8 0b 2d 45 ff 48 89 df 57 9d <0f> 1f 44 00 00 48 8b 5d f0 4c 8b 65 f8 c9 c3 0f 1f 80 00 00 00 Tommi