INFO: task kworker/u4:2:26 blocked for more than 143 seconds. Not tainted 5.9.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:27288 pid: 26 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 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 cangw_pernet_exit+0xe/0x20 net/can/gw.c:1180 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186 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.2:11061 blocked for more than 143 seconds. Not tainted 5.9.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:25352 pid:11061 ppid: 6975 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 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:9266 unregister_netdevice_many.part.0+0x1a/0x2f0 net/core/dev.c:10426 unregister_netdevice_many+0x36/0x50 net/core/dev.c:10425 ip6_tnl_exit_batch_net+0x46c/0x670 net/ipv6/ip6_tunnel.c:2323 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:189 setup_net+0x502/0x850 net/core/net_namespace.c:364 copy_net_ns+0x2cf/0x5e0 net/core/net_namespace.c:482 create_new_namespaces+0x3f6/0xb10 kernel/nsproxy.c:110 copy_namespaces+0x385/0x470 kernel/nsproxy.c:179 copy_process+0x294b/0x6920 kernel/fork.c:2072 _do_fork+0xe8/0xb10 kernel/fork.c:2428 __do_sys_clone+0xc8/0x110 kernel/fork.c:2545 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: Bad RIP value. RSP: 002b:00007f571f8bbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000001f40 RCX: 000000000045d4d9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00000000e1004d7c RBP: 000000000118cf90 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 000000000169fb6f R14: 00007f571f8bc9c0 R15: 000000000118cf4c INFO: task syz-executor.2:11132 blocked for more than 144 seconds. Not tainted 5.9.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27584 pid:11132 ppid: 6975 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 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 gtp_net_exit+0x1b5/0x380 drivers/net/gtp.c:1353 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186 setup_net+0x502/0x850 net/core/net_namespace.c:364 copy_net_ns+0x2cf/0x5e0 net/core/net_namespace.c:482 create_new_namespaces+0x3f6/0xb10 kernel/nsproxy.c:110 copy_namespaces+0x385/0x470 kernel/nsproxy.c:179 copy_process+0x294b/0x6920 kernel/fork.c:2072 _do_fork+0xe8/0xb10 kernel/fork.c:2428 __do_sys_clone+0xc8/0x110 kernel/fork.c:2545 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: Bad RIP value. RSP: 002b:00007f571f879c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000001f40 RCX: 000000000045d4d9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00000000e1004d7c RBP: 000000000118d0d0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d08c R13: 000000000169fb6f R14: 00007f571f87a9c0 R15: 000000000118d08c INFO: task syz-executor.4:11166 blocked for more than 145 seconds. Not tainted 5.9.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27872 pid:11166 ppid: 7149 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 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 gtp_net_exit+0x1b5/0x380 drivers/net/gtp.c:1353 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186 setup_net+0x502/0x850 net/core/net_namespace.c:364 copy_net_ns+0x2cf/0x5e0 net/core/net_namespace.c:482 create_new_namespaces+0x3f6/0xb10 kernel/nsproxy.c:110 copy_namespaces+0x385/0x470 kernel/nsproxy.c:179 copy_process+0x294b/0x6920 kernel/fork.c:2072 _do_fork+0xe8/0xb10 kernel/fork.c:2428 __do_sys_clone+0xc8/0x110 kernel/fork.c:2545 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: Bad RIP value. RSP: 002b:00007fcae2ac0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000001f40 RCX: 000000000045d4d9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00000000e1004d7c RBP: 000000000118d0d0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d08c R13: 000000000169fb6f R14: 00007fcae2ac19c0 R15: 000000000118d08c Showing all locks held in the system: 4 locks held by kworker/u4:2/26: #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: ffffc90000e27da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8a7da030 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa00 net/core/net_namespace.c:565 #3: ffffffff8a7e7088 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit+0xe/0x20 net/can/gw.c:1180 1 lock held by khungtaskd/1170: #0: ffffffff89bd6340 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5825 3 locks held by kworker/0:2/2716: #0: ffff88809abba938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88809abba938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88809abba938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88809abba938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88809abba938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88809abba938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc900092f7da8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8a7e7088 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4582 6 locks held by kworker/0:1H/2874: 1 lock held by in:imklog/6521: #0: ffff8880a83d1430 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by agetty/6528: #0: ffff8880a136b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000f642e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 2 locks held by agetty/6538: #0: ffff88808f61a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000f742e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.2/11061: #0: ffffffff8a7da030 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478 #1: ffffffff8a7e7088 (rtnl_mutex){+.+.}-{3:3}, at: ip6_tnl_exit_batch_net+0x82/0x670 net/ipv6/ip6_tunnel.c:2320 #2: ffffffff89b91010 (cpu_hotplug_lock){++++}-{0:0}, at: get_online_cpus include/linux/cpu.h:144 [inline] #2: ffffffff89b91010 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:5628 [inline] #2: ffffffff89b91010 (cpu_hotplug_lock){++++}-{0:0}, at: rollback_registered_many+0x45b/0x1210 net/core/dev.c:9266 2 locks held by syz-executor.2/11132: #0: ffffffff8a7da030 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478 #1: ffffffff8a7e7088 (rtnl_mutex){+.+.}-{3:3}, at: gtp_net_exit+0x1b5/0x380 drivers/net/gtp.c:1353 2 locks held by syz-executor.4/11166: #0: ffffffff8a7da030 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478 #1: ffffffff8a7e7088 (rtnl_mutex){+.+.}-{3:3}, at: gtp_net_exit+0x1b5/0x380 drivers/net/gtp.c:1353 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1170 Comm: khungtaskd Not tainted 5.9.0-rc1-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+0x18f/0x20d 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2874 Comm: kworker/0:1H Not tainted 5.9.0-rc1-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:mark_held_locks+0x59/0xe0 kernel/locking/lockdep.c:3601 Code: 74 08 3c 03 0f 8e 89 00 00 00 41 8b 84 24 e0 08 00 00 31 db 49 bd 00 00 00 00 00 fc ff df 4d 8d b4 24 e8 08 00 00 85 c0 7e 57 <48> 63 c3 48 8d 04 80 49 8d 34 c6 48 8d 7e 22 48 89 f8 48 89 fa 48 RSP: 0018:ffffc900096d7b58 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000000 RCX: 1ffffffff1563e91 RDX: 1ffff11013b0b9b4 RSI: 0000000000000002 RDI: ffff88809d85cda0 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88809d85c4c0 R13: dffffc0000000000 R14: ffff88809d85cda8 R15: ffff8880a970e3a0 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000747698 CR3: 00000000a3a22000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:3629 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:3697 [inline] lockdep_hardirqs_on_prepare+0x19c/0x530 kernel/locking/lockdep.c:3649 trace_hardirqs_on+0x5f/0x220 kernel/trace/trace_preemptirq.c:49 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x62/0xe0 kernel/locking/spinlock.c:191 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] snd_midi_event_encode_byte sound/core/seq/seq_midi_event.c:239 [inline] snd_midi_event_encode_byte+0x278/0xcf0 sound/core/seq/seq_midi_event.c:176 snd_vmidi_output_work+0x147/0x380 sound/core/seq/seq_virmidi.c:146 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