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=-5.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 ADD2FC49ED9 for ; Tue, 10 Sep 2019 19:18:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82B3221019 for ; Tue, 10 Sep 2019 19:18:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727958AbfIJTSK (ORCPT ); Tue, 10 Sep 2019 15:18:10 -0400 Received: from mail-io1-f69.google.com ([209.85.166.69]:35502 "EHLO mail-io1-f69.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725263AbfIJTSJ (ORCPT ); Tue, 10 Sep 2019 15:18:09 -0400 Received: by mail-io1-f69.google.com with SMTP id 18so24488505iof.2 for ; Tue, 10 Sep 2019 12:18:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=qJrPEyyq2wIkvZMXDLhRyvs6qoso+R0H+MG2NHGwSu4=; b=gmlgyHS3Y19gDPaXgvTABzOT7Qfn0H7NbDPluLOxwH4zCDZkXclfvk538ziBjZbwgl +3PTuSK8Y/NYplXCFD9e+Ds1oIaaUl+OvH+fPT4yx2AHnLMukJJISxCMIcskuRhMZevY 6+jNtSuLvDOClP2mHj5ZDiIGpIFOM/OKqxaDxDJujIjRkAqYlsViLAMHT1Ir7CmdWBQk d7U80y1W29o6umaBaXs5ESeUg2B0p/RorxXsFRVK+ksintT+KE2X5v9E+IHaQrxB4K3p i4Kvio3Zo61hhUaWwOl/kw/TxTPlKbxpX4GqGNGW87q7fhNgrNC0RqRAqKzCVdr1Lb11 IkGQ== X-Gm-Message-State: APjAAAX70wNImt+lFW8wNNLitiZoRjicAYH3B8iyp7hjM8Rt1Is/FoWi UVW3/UrhTTbhyP2Da7b8aITyrt7pAB3xVmhnzdDIWo7U9BwZ X-Google-Smtp-Source: APXvYqwLp6TUDoXjKFeiVSnFe2tcLGdqsf8aJ3drx9I589lEwG+oRCppTSFpEhF9UmKXSYXlIfIgfWkn3OCz1rX4NX6lvbb6MkDc MIME-Version: 1.0 X-Received: by 2002:a02:948c:: with SMTP id x12mr32825055jah.96.1568143088627; Tue, 10 Sep 2019 12:18:08 -0700 (PDT) Date: Tue, 10 Sep 2019 12:18:08 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000c1391b059237c3a6@google.com> Subject: INFO: rcu detected stall in addrconf_dad_work From: syzbot To: davem@davemloft.net, jhs@mojatatu.com, jiri@resnulli.us, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, xiyou.wangcong@gmail.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 3b47fd5c Merge tag 'nfs-for-5.3-4' of git://git.linux-nfs... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=126c0f51600000 kernel config: https://syzkaller.appspot.com/x/.config?x=b89bb446a3faaba4 dashboard link: https://syzkaller.appspot.com/bug?extid=0055e43d6f67fb9b8ba1 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1500264e600000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d7a46e600000 Bisection is inconclusive: the bug happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=160261e1600000 console output: https://syzkaller.appspot.com/x/log.txt?x=110261e1600000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+0055e43d6f67fb9b8ba1@syzkaller.appspotmail.com rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=e02/1/0x4000000000000002 softirq=9705/9705 fqs=4 (t=10500 jiffies g=9309 q=84) rcu: rcu_preempt kthread starved for 10492 jiffies! g9309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29112 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xd9/0x260 kernel/sched/core.c:3947 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 3027 Comm: kworker/1:2 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2736 [inline] rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__list_del_entry_valid+0x4b/0xf5 lib/list_debug.c:45 Code: 54 80 3c 02 00 0f 85 a1 00 00 00 4c 89 f2 4d 8b 66 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 9d 00 00 00 <48> b8 00 01 00 00 00 00 ad de 4d 8b 2e 49 39 c5 0f 84 e1 00 00 00 RSP: 0018:ffff88809ff26d30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff88808c560778 RCX: ffffffff85c64b39 RDX: 1ffff110118ac0ef RSI: ffffffff85c65006 RDI: ffff88808c560780 RBP: ffff88809ff26d48 R08: ffff88809ff08300 R09: 0000000000000000 R10: fffffbfff134af8f R11: ffff88809ff08300 R12: ffff88808c560810 R13: ffff88808c560480 R14: ffff88808c560778 R15: 0000000000000000 __list_del_entry include/linux/list.h:131 [inline] list_move_tail include/linux/list.h:213 [inline] hhf_dequeue+0x5c5/0xa20 net/sched/sch_hhf.c:439 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x16f1/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] __br_forward+0x641/0xb00 net/bridge/br_forward.c:109 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125 maybe_deliver+0x2c7/0x390 net/bridge/br_forward.c:181 br_flood+0x13a/0x3d0 net/bridge/br_forward.c:223 br_dev_xmit+0x98c/0x15a0 net/bridge/br_device.c:100 __netdev_start_xmit include/linux/netdevice.h:4406 [inline] netdev_start_xmit include/linux/netdevice.h:4420 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 neigh_resolve_output net/core/neighbour.c:1490 [inline] neigh_resolve_output+0x5a5/0x970 net/core/neighbour.c:1470 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x1034/0x2520 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x444/0xa50 net/ipv6/ip6_output.c:142 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7c0 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0xf29/0x1450 net/ipv6/ndisc.c:504 ndisc_send_ns+0x3a9/0x850 net/ipv6/ndisc.c:646 addrconf_dad_work+0xb88/0x1150 net/ipv6/addrconf.c:4120 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 --- 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. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches