INFO: task syz-executor:8182 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25688 pid:8182  tgid:8182  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 ip_tunnel_init_net+0x2ab/0x800
 ops_init+0x35c/0x5c0
 setup_net+0x110/0x330
 copy_net_ns+0x3e3/0x570
 create_new_namespaces+0x3e7/0x6a0
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c70190fc7
RSP: 002b:00007ffcd4f11ed8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f2c703e5f40 RCX: 00007f2c70190fc7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f2c703e67b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffcd4f121a8 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:8190 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:27032 pid:8190  tgid:8190  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 inet_rtm_newaddr+0x3b0/0x18b0
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f897af9165c
RSP: 002b:00007ffdeea74d20 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f897bd14620 RCX: 00007f897af9165c
RDX: 0000000000000028 RSI: 00007f897bd14670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffdeea74d74 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f897bd14670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:8192 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:26904 pid:8192  tgid:8192  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 inet_rtm_newaddr+0x3b0/0x18b0
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5fdd59165c
RSP: 002b:00007ffef838f8a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f5fde314620 RCX: 00007f5fdd59165c
RDX: 0000000000000028 RSI: 00007f5fde314670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffef838f8f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f5fde314670 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff88816afed148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90000127bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
1 lock held by khungtaskd/35:
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/0:3/5300:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc9000361fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
1 lock held by dhcpcd/5579:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20
2 locks held by getty/5660:
 #0: ffff8881767500a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900035732f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460
1 lock held by udevd/5832:
 #0: ffff888109950358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by kworker/u8:4/5869:
3 locks held by kworker/u10:39/7766:
 #0: ffff888100089948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90003b1fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
5 locks held by kworker/u8:8/8047:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90008c1fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f304bb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0
 #3: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990
 #4: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2b1/0x6e0
2 locks held by syz-executor/8176:
 #0: ffffffff8f304bb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120
2 locks held by syz-executor/8178:
 #0: ffffffff8f304bb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120
2 locks held by syz-executor/8182:
 #0: ffffffff8f304bb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800
1 lock held by syz-executor/8190:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8192:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8196:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8199:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8200:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8210:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8212:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8215:
 #0: ffffffff8f311c48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf95/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x510/0xa50
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:unwind_next_frame+0x184d/0x23d0
Code: 8b 54 24 08 48 8d 5a 02 48 83 c2 03 48 89 d8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 4a 0a 00 00 48 89 d0 48 c1 e8 03 0f b6 04 28 <84> c0 48 8b 74 24 18 0f 85 57 0a 00 00 48 0f bf 03 48 01 c6 49 8d
RSP: 0018:ffffc900001d6918 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: ffffffff90a96af4 RCX: 0000000000000000
RDX: ffffffff90a96af5 RSI: 0000000000000001 RDI: ffffc900001d6a48
RBP: dffffc0000000000 R08: ffffc900001d6a47 R09: 0000000000000000
R10: ffffc900001d6a38 R11: fffff5200003ad49 R12: ffffc900001d6a38
R13: 1ffff9200003ad3f R14: ffffc900001d69e8 R15: 1ffffffff2152d5e
FS:  0000000000000000(0000) GS:ffff8882a9e21000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3884ca91a0 CR3: 000000000dd3a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x37d/0x710
 skb_ext_add+0x1b6/0x8f0
 br_nf_forward_ip+0xc6/0x7e0
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x215/0x3c0
 __br_forward+0x397/0x540
 br_handle_frame_finish+0x15a3/0x1c90
 br_nf_hook_thresh+0x3c6/0x4a0
 br_nf_pre_routing_finish_ipv6+0x999/0xd60
 br_nf_pre_routing_ipv6+0x37e/0x6b0
 br_handle_frame+0x96e/0x14f0
 __netif_receive_skb_core+0x95f/0x2f90
 __netif_receive_skb+0x72/0x380
 process_backlog+0x54f/0x1340
 __napi_poll+0xae/0x320
 net_rx_action+0x64a/0xe00
 handle_softirqs+0x22b/0x7c0
 run_ksoftirqd+0x36/0x60
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x510/0xa50
 ret_from_fork_asm+0x1a/0x30
 </TASK>
