INFO: task kworker/u8:4:339 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:0     pid:339   tgid:339   ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134a/0x1dd0 kernel/sched/core.c:7842
 __schedule_loop kernel/sched/core.c:7923 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7938
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7995
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 addrconf_verify_work+0x1d/0x50 net/ipv6/addrconf.c:4774
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c6/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor:384 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:384   tgid:384   ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134a/0x1dd0 kernel/sched/core.c:7842
 __schedule_loop kernel/sched/core.c:7923 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7938
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7995
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 ppp_exit_net+0x12d/0x360 drivers/net/ppp/ppp_generic.c:1158
 ops_exit_list net/core/net_namespace.c:173 [inline]
 setup_net+0x685/0x9b0 net/core/net_namespace.c:388
 copy_net_ns+0x512/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x502/0x880 kernel/fork.c:3354
 __do_sys_unshare kernel/fork.c:3425 [inline]
 __se_sys_unshare kernel/fork.c:3423 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3423
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f61fbd9c1a7
RSP: 002b:00007ffc80b34bc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f61fc015f40 RCX: 00007f61fbd9c1a7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f61fc0167b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffc80b34e08 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:394 blocked for more than 128 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:394   tgid:394   ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134a/0x1dd0 kernel/sched/core.c:7842