INFO: task dhcpcd:5337 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:21672 pid:5337  tgid:5337  ppid:5336   task_flags:0x400140 flags:0x00080800
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 rtnl_dumpit+0x92/0x200
 netlink_dump+0x711/0xee0
 __netlink_dump_start+0x589/0x7b0
 rtnetlink_rcv_msg+0xa48/0xc00
 netlink_rcv_skb+0x226/0x4a0
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f11bbddaad7
RSP: 002b:00007ffd1e4aab68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffd1e4abc90 RCX: 00007f11bbddaad7
RDX: 0000000000000014 RSI: 00007ffd1e4abbb0 RDI: 0000000000000013
RBP: 00007ffd1e4abc20 R08: 00007ffd1e4abb94 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016
R13: 00007ffd1e4abb94 R14: 00007ffd1e4abbb0 R15: 0000000000000105
 </TASK>
INFO: task kworker/u10:11:6509 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:11  state:D stack:22568 pid:6509  tgid:6509  ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 linkwatch_event+0xe/0x60
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz-executor:21771 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:25704 pid:21771 tgid:21771 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 unregister_netdevice_notifier_net+0x18/0x60
 ops_undo_list+0x43d/0x8d0
 setup_net+0x2f6/0x350
 copy_net_ns+0x53b/0x780
 create_new_namespaces+0x3f0/0x6b0
 unshare_nsproxy_namespaces+0x149/0x190
 ksys_unshare+0x5a7/0x950
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f818259f427
RSP: 002b:00007ffc32ec8f08 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f8182825f40 RCX: 00007f818259f427
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f81828267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffc32ec9148 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:21789 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:24456 pid:21789 tgid:21789 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x87d/0x1080
 down_write+0x1bc/0x200
 rdma_dev_exit_net+0x8b/0x430
 ops_undo_list+0x43d/0x8d0
 setup_net+0x2f6/0x350
 copy_net_ns+0x53b/0x780
 create_new_namespaces+0x3f0/0x6b0
 unshare_nsproxy_namespaces+0x149/0x190
 ksys_unshare+0x5a7/0x950
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6738f9f427
RSP: 002b:00007fffb80ffab8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f6739225f40 RCX: 00007f6738f9f427
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f67392267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fffb80ffcf8 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:21813 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:25544 pid:21813 tgid:21813 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 ip_tunnel_init_net+0x2d5/0x820
 ops_init+0x35d/0x5d0
 setup_net+0x118/0x350
 copy_net_ns+0x53b/0x780
 create_new_namespaces+0x3f0/0x6b0
 unshare_nsproxy_namespaces+0x149/0x190
 ksys_unshare+0x5a7/0x950
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e0279f427
RSP: 002b:00007ffffc4dcba8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f5e02a25f40 RCX: 00007f5e0279f427
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f5e02a267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffffc4dcde8 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:21821 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:26616 pid:21821 tgid:21821 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 ib_get_eth_speed+0x173/0x7f0
 rxe_query_port+0x93/0x3d0
 ib_query_port+0x16e/0x830
 ib_setup_port_attrs+0x294/0x2420
 add_one_compat_dev+0x446/0x650
 rdma_dev_init_net+0x243/0x2f0
 ops_init+0x35d/0x5d0
 setup_net+0x118/0x350
 copy_net_ns+0x53b/0x780
 create_new_namespaces+0x3f0/0x6b0
 unshare_nsproxy_namespaces+0x149/0x190
 ksys_unshare+0x5a7/0x950
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff853d9f427
RSP: 002b:00007ffe3d05a658 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007ff854025f40 RCX: 00007ff853d9f427
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007ff8540267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffe3d05a898 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:21837 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:26616 pid:21837 tgid:21837 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6ba/0x920
 down_read+0x9c/0x330
 rdma_dev_init_net+0x238/0x2f0
 ops_init+0x35d/0x5d0
 setup_net+0x118/0x350
 copy_net_ns+0x53b/0x780
 create_new_namespaces+0x3f0/0x6b0
 unshare_nsproxy_namespaces+0x149/0x190
 ksys_unshare+0x5a7/0x950
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbdbad9f427
RSP: 002b:00007ffe53b7e0e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fbdbb025f40 RCX: 00007fbdbad9f427
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fbdbb0267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffe53b7e328 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:21864 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:25544 pid:21864 tgid:21864 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 rtnl_newlink+0xc10/0x1c30
 rtnetlink_rcv_msg+0x802/0xc00
 netlink_rcv_skb+0x226/0x4a0
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f835c55e98e
RSP: 002b:00007ffd6fb60158 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555573c82500 RCX: 00007f835c55e98e
RDX: 000000000000002c RSI: 00007f835d354670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd6fb601d4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f835d354670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:21870 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:26616 pid:21870 tgid:21870 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 rtnl_newlink+0xc10/0x1c30
 rtnetlink_rcv_msg+0x802/0xc00
 netlink_rcv_skb+0x226/0x4a0
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 __sys_sendto+0x408/0x5a0
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faf0195e98e
RSP: 002b:00007ffdb14bad58 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555569199500 RCX: 00007faf0195e98e
RDX: 000000000000002c RSI: 00007faf02754670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffdb14badd4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007faf02754670 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
locks held by kworker/0:0/9: 3, on CPU#0:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900000e7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
locks held by kworker/u8:1/13: 4, last CPU#1:
 #0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff90242088 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810
 #3: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0
locks held by pr/ttyS0/16: 1, last CPU#0:
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60
locks held by khungtaskd/34: 1, last CPU#0:
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by kworker/u10:4/1107: 2, last CPU#1:
 #0: ffff8881000ab940 ((wq_completion)events_dfl_long){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90006e57c40 ((work_completion)(&(&ipvs->defense_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by klogd/5030: 1, last CPU#0:
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x550
locks held by dhcpcd/5337: 2, on CPU#1:
 #0: ffff8881a82c36e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0
 #1: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200
locks held by getty/5416: 2, on CPU#1:
 #0: ffff888110a780a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034832e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by sshd/5514: 3, last CPU#1:
 #0: ffff8881076e0260 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x21/0x50
 #1: ffffffff8eeabc30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
 #2: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: __update_page_owner_free_handle+0x2e/0x4a0
locks held by syz-executor/5526: 3, last CPU#1:
 #0: ffff88817482dcf8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0
 #1: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550
 #2: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x3de/0x18b0
locks held by kworker/u8:3/5650: 3, on CPU#0:
 #0: ffff88810eec5940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000468fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
locks held by kworker/u10:11/6509: 3, on CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90003f1fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
locks held by kworker/0:15/6590: 3, on CPU#0:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90003b5fc40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x6f/0x770
locks held by kworker/u8:5/20448: 2, last CPU#1:
 #0: ffff88810f5ff940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90007877c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by syz-executor/21771: 2, on CPU#0:
 #0: ffffffff90242088 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780
 #1: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x18/0x60
locks held by syz-executor/21789: 2, on CPU#1:
 #0: ffffffff90242088 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780
 #1: ffffffff8ff9dbc8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x8b/0x430
locks held by syz-executor/21813: 2, on CPU#0:
 #0: ffffffff90242088 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780
 #1: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x820
locks held by syz-executor/21821: 6, on CPU#0:
 #0: ffffffff90242088 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780
 #1: ffffffff8ff9da08 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0
 #2: ffffffff8ff9dbc8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0
 #3: ffff8881bb425020 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650
 #4: ffff8881bb425310 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0
 #5: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0
locks held by syz-executor/21837: 3, on CPU#0:
 #0: ffffffff90242088 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780
 #1: ffffffff8ff9da08 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0
 #2: ffffffff8ff9dbc8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0
locks held by syz-executor/21864: 1, on CPU#1:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30
locks held by syz-executor/21870: 1, on CPU#0:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30
locks held by syz-executor/21884: 1, on CPU#0:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/21892: 1, on CPU#1:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/21898: 1, on CPU#0:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/21906: 1, on CPU#0:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/21913: 1, on CPU#0:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/21919: 1, on CPU#1:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/21927: 1, on CPU#1:
 #0: ffffffff902508e0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 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+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 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: 5023 Comm: syslogd 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+0xae5/0x2550
Code: 48 85 ff 0f 84 b9 0d 00 00 48 83 c7 70 e8 c3 25 00 00 49 89 c0 48 8b 54 24 08 48 8d 5a 01 48 8b 44 24 30 42 0f b6 04 20 84 c0 <4c> 89 04 24 0f 85 26 14 00 00 48 89 dd 48 c1 ed 03 42 0f b6 44 25
RSP: 0018:ffffc90000a17e80 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff91a9c283 RCX: ffffffff90f87cfc
RDX: ffffffff91a9c282 RSI: ffffffff91a9c27e RDI: ffffffff8c6d9420
RBP: ffffc90000a17f60 R08: ffffc90000a18440 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: dffffc0000000000
R13: ffffffff91a9c27e R14: ffffc90000a17f28 R15: 1ffff92000142fe5
FS:  00007f816a755380(0000) GS:ffff8882a8cd8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffde46e2ce8 CR3: 00000001117be000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x2b9/0x600
 skb_clone+0x212/0x3a0
 br_flood+0x616/0x8d0
 br_handle_frame_finish+0x1119/0x1950
 br_nf_hook_thresh+0x3dd/0x4c0
 br_nf_pre_routing_finish_ipv6+0x90c/0xc40
 br_nf_pre_routing_ipv6+0x382/0x6f0
 br_handle_frame+0x127f/0x1510
 __netif_receive_skb_core+0x989/0x30c0
 process_backlog+0x727/0x18b0
 __napi_poll+0xaa/0x330
 net_rx_action+0x61d/0xf50
 handle_softirqs+0x226/0x860
 __irq_exit_rcu+0xcb/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:rcu_is_watching+0x2f/0xb0
Code: 57 41 56 53 65 48 ff 05 6f 31 e8 11 e8 0a 43 38 0a 89 c3 83 f8 08 73 66 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 67 74 8e <4c> 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 bb 35 8b 00
RSP: 0018:ffffc900068874e0 EFLAGS: 00000297
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 8000000000000001
RDX: 00000000d6aa1001 RSI: ffffffff8c6d9460 RDI: ffffffff8c6d9420
RBP: 1ffff92000d10ebc R08: 8f00000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: dffffc0000000000
R13: ffffffff8177f22f R14: ffffffff8e7467d8 R15: dffffc0000000000
 unwind_next_frame+0xbe/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x5c/0x80
 kmem_cache_free+0x182/0x650
 __unix_dgram_recvmsg+0x9e1/0xd70
 sock_recvmsg+0x196/0x1e0
 sock_read_iter+0x22a/0x2f0
 vfs_read+0x595/0xa80
 ksys_read+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f816a8a9b6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffdb0c8b6a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f816a8a9b6a
RDX: 00000000000000ff RSI: 0000558182e1f950 RDI: 0000000000000000
RBP: 0000558182e1f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000558182e1ff00 R11: 0000000000000246 R12: 0000558182e1f9b3
R13: 0000558182e1f950 R14: 0000000000000000 R15: 00007f816aa8ea80
 </TASK>
