INFO: task kworker/u8:9:3349 blocked for more than 148 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:22944 pid:3349  tgid:3349  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 linkwatch_event+0xe/0x60 net/core/link_watch.c:313
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor:5785 blocked for more than 148 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22280 pid:5785  tgid:5785  ppid:5779   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
 inet6_rtm_newaddr+0x667/0xe00 net/ipv6/addrconf.c:5063
 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7137
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
 __sock_sendmsg net/socket.c:815 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2281
 __do_sys_sendto net/socket.c:2288 [inline]
 __se_sys_sendto net/socket.c:2284 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2284
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f58c595e98e
RSP: 002b:00007ffe176106d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00005555854ce500 RCX: 00007f58c595e98e
RDX: 0000000000000040 RSI: 00007f58c6754670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffe17610754 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f58c6754670 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
locks held by kthreadd/2: 1, last CPU#1:
 #0: ffffffff8eeac770 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
 #0: ffffffff8eeac770 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:305
locks held by kworker/R-kvfre/6: 1, on CPU#1:
 #0: ffffffff8ebf92a0 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x31/0x390 kernel/workqueue.c:2786
locks held by kworker/0:0/9: 3, last CPU#0:
 #0: ffff88807ae8f540 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88807ae8f540 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88807ae8f540 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88807ae8f540 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479