syzbot


INFO: task hung in ip6_tnl_exit_batch_net

Status: auto-closed as invalid on 2020/12/11 16:12
Subsystems: net
[Documentation on labels]
First crash: 1422d, last: 1293d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ip6_tnl_exit_batch_net (3) net 1 401d 401d 0/26 auto-obsoleted due to no activity on 2023/05/22 13:26
upstream INFO: task hung in ip6_tnl_exit_batch_net (2) net 1 638d 638d 0/26 auto-closed as invalid on 2022/09/27 10:20

Sample crash report:
INFO: task kworker/u4:10:32031 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:10   state:D stack:25832 pid:32031 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x163/0x260 kernel/sched/completion.c:138
 __flush_work+0x51f/0xab0 kernel/workqueue.c:3046
 flush_all_backlogs net/core/dev.c:5635 [inline]
 rollback_registered_many+0x552/0x1210 net/core/dev.c:9269
 unregister_netdevice_many.part.0+0x1a/0x2f0 net/core/dev.c:10429
 unregister_netdevice_many+0x36/0x50 net/core/dev.c:10428
 ip6_tnl_exit_batch_net+0x46c/0x670 net/ipv6/ip6_tunnel.c:2331
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:189
 cleanup_net+0x4ea/0xa00 net/core/net_namespace.c:603
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
INFO: task syz-executor.5:5547 blocked for more than 144 seconds.
      Not tainted 5.9.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:27288 pid: 5547 ppid:  7208 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
 ip_tunnel_init_net+0x31c/0x980 net/ipv4/ip_tunnel.c:1071
 ops_init+0xaf/0x470 net/core/net_namespace.c:151
 setup_net+0x2d8/0x850 net/core/net_namespace.c:341
 copy_net_ns+0x2cf/0x5e0 net/core/net_namespace.c:482
 create_new_namespaces+0x3f6/0xb10 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:231
 ksys_unshare+0x445/0x8e0 kernel/fork.c:2921
 __do_sys_unshare kernel/fork.c:2989 [inline]
 __se_sys_unshare kernel/fork.c:2987 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:2987
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5f9
Code: Bad RIP value.
RSP: 002b:00007fe46942cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000036500 RCX: 000000000045d5f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060060280
RBP: 000000000118d010 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 000000000169fb6f R14: 00007fe46942d9c0 R15: 000000000118cfec

Showing all locks held in the system:
1 lock held by khungtaskd/1169:
 #0: ffffffff89bd6a40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829
6 locks held by kworker/1:1H/2452:
3 locks held by kworker/1:2/2462:
 #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc90008537da8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
 #2: ffffffff8a7ea788 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
1 lock held by in:imklog/6565:
 #0: ffff8880a8327670 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
2 locks held by agetty/6764:
 #0: ffff8880a27f5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900016482e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156
2 locks held by agetty/6765:
 #0: ffff8880a656c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900015fc2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156
2 locks held by agetty/6766:
 #0: ffff8880906f2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc9000163c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156
5 locks held by kworker/u4:10/32031:
 #0: ffff8880a97b5138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8880a97b5138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff8880a97b5138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff8880a97b5138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff8880a97b5138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff8880a97b5138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc90008977da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
 #2: ffffffff8a7dd730 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa00 net/core/net_namespace.c:565
 #3: ffffffff8a7ea788 (rtnl_mutex){+.+.}-{3:3}, at: ip6_tnl_exit_batch_net+0x82/0x670 net/ipv6/ip6_tunnel.c:2328
 #4: ffffffff89b91650 (cpu_hotplug_lock){++++}-{0:0}, at: get_online_cpus include/linux/cpu.h:144 [inline]
 #4: ffffffff89b91650 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:5628 [inline]
 #4: ffffffff89b91650 (cpu_hotplug_lock){++++}-{0:0}, at: rollback_registered_many+0x45b/0x1210 net/core/dev.c:9269
3 locks held by kworker/1:4/2109:
 #0: ffff888214cff138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888214cff138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888214cff138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888214cff138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff888214cff138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff888214cff138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc900163cfda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
 #2: ffffffff8a7ea788 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568
2 locks held by syz-executor.5/5547:
 #0: ffffffff8a7dd730 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478
 #1: ffffffff8a7ea788 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x31c/0x980 net/ipv4/ip_tunnel.c:1071

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1169 Comm: khungtaskd Not tainted 5.9.0-rc4-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+0x198/0x1fd lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2452 Comm: kworker/1:1H Not tainted 5.9.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:strlen+0x5c/0x90 lib/string.c:544
Code: 48 bb 00 00 00 00 00 fc ff df 48 89 e8 48 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 0f b6 14 1a 38 ca 7f 04 84 d2 75 1f <80> 38 00 75 de 48 83 c4 08 48 29 e8 5b 5d c3 48 83 c4 08 31 c0 5b
RSP: 0018:ffffc90007baf868 EFLAGS: 00000002
RAX: ffffffff884b44e8 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffff8880ae735e18 RDI: ffffffff884b44e0
RBP: ffffffff884b44e0 R08: 0000000000000000 R09: ffffffff8ab26c0f
R10: fffffbfff1564d81 R11: 0000000000000000 R12: ffffffff81597ab0
R13: ffffffff89bbd400 R14: ffff8880ae735e18 R15: ffffc90007baf938
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c018010000 CR3: 00000002098cd000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 strlen include/linux/string.h:328 [inline]
 trace_event_get_offsets_lock include/trace/events/lock.h:39 [inline]
 perf_trace_lock+0xb1/0x4a0 include/trace/events/lock.h:39
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x5d1/0x8f0 kernel/locking/lockdep.c:5017
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:166 [inline]
 _raw_spin_unlock_irq+0x12/0x80 kernel/locking/spinlock.c:199
 finish_lock_switch kernel/sched/core.c:3517 [inline]
 finish_task_switch+0x147/0x750 kernel/sched/core.c:3617
 context_switch kernel/sched/core.c:3781 [inline]
 __schedule+0xeb1/0x2230 kernel/sched/core.c:4527
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:4683
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:40
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
 _raw_spin_unlock_irqrestore+0x78/0x90 kernel/locking/spinlock.c:191
 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline]
 snd_rawmidi_transmit+0xc1/0xf0 sound/core/rawmidi.c:1316
 snd_vmidi_output_work+0x108/0x380 sound/core/seq/seq_virmidi.c:144
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/09/12 16:10 upstream 729e3d091984 ce441f06 .config console log report ci-upstream-kasan-gce
2020/06/30 07:16 upstream 4e99b32169e8 a2cdad9d .config console log report ci-upstream-kasan-gce
2020/05/06 22:33 upstream 3c40cdb0e93e 4618eb2d .config console log report ci-upstream-kasan-gce-root
* Struck through repros no longer work on HEAD.