INFO: task hung in macvtap_device_event

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: c10b57a5 Linux 4.14.176
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15944c73e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=457897b554d08537
dashboard link: https://syzkaller.appspot.com/bug?extid=d9a999afc622d2c1016c
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d9a999...@syzkaller.appspotmail.com

bridge0: port 1(bridge_slave_0) entered disabled state
device veth1_macvtap left promiscuous mode
device veth0_macvtap left promiscuous mode
device veth1_vlan left promiscuous mode
device veth0_vlan left promiscuous mode
INFO: task kworker/u4:0:5 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:0 D26944 5 2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
kobject_uevent_env+0x5a4/0xc50 lib/kobject_uevent.c:459
device_del+0x642/0xa80 drivers/base/core.c:2081
device_unregister drivers/base/core.c:2103 [inline]
device_destroy+0x86/0xb0 drivers/base/core.c:2661
macvtap_device_event+0x220/0x360 drivers/net/macvtap.c:187
notifier_call_chain+0x107/0x1a0 kernel/notifier.c:93
call_netdevice_notifiers net/core/dev.c:1687 [inline]
rollback_registered_many+0x694/0xa70 net/core/dev.c:7205
unregister_netdevice_many.part.0+0x16/0x1d0 net/core/dev.c:8278
unregister_netdevice_many net/core/dev.c:8277 [inline]
default_device_exit_batch+0x2dd/0x380 net/core/dev.c:8739
ops_exit_list.isra.0+0xef/0x140 net/core/net_namespace.c:145
cleanup_net+0x3bb/0x820 net/core/net_namespace.c:484
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/0:2:2858 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:2 D27120 2858 2 0x80000000
Workqueue: events linkwatch_event
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
linkwatch_event+0xa/0x50 net/core/link_watch.c:236
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/0:1:13379 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:1 D27976 13379 2 0x80000000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4412
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/0:4:14868 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:4 D28960 14868 2 0x80000000
Workqueue: events switchdev_deferred_process_work
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task syz-executor.1:16146 blocked for more than 140 seconds.
Not tainted 4.14.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D28688 16146 1 0x00000004
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4310
netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313
netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.