Issue

• The server looks to hang or becomes unresponsive after Centrify's adclient crashes.
• A Hung Task report related to adclient can be seen on the kernel log:

INFO: task adclient:1428 blocked for more than 120 seconds.
      Not tainted 2.6.32-504.16.2.el6.x86_64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
adclient      D 0000000000000000     0  1428      1 0x00000080
 ffff88013cf21c98 0000000000000082 0000000000000000 ffff88013cf21c88
 ffff88013cf21c90 ffff880139991520 ffff88013cf21c68 ffffffff810b2e60
 ffffc900006275c4 0000000000000000 ffff880139991ad8 ffff88013cf21fd8
Call Trace:
 [<ffffffff810b2e60>] ? exit_robust_list+0x90/0x160
 [<ffffffff81079ad5>] exit_mm+0x95/0x180
 [<ffffffff81079f1f>] do_exit+0x15f/0x870
 [<ffffffff8107a688>] do_group_exit+0x58/0xd0
 [<ffffffff81090336>] get_signal_to_deliver+0x1f6/0x460
 [<ffffffff8100a265>] do_signal+0x75/0x800
 [<ffffffff81448c35>] ? sys_sendto+0x185/0x190
 [<ffffffff810b57bb>] ? sys_futex+0x7b/0x170
 [<ffffffff8100aa80>] do_notify_resume+0x90/0xc0
 [<ffffffff8100b341>] int_signal+0x12/0x17
Kernel panic - not syncing: hung_task: blocked tasks
Pid: 39, comm: khungtaskd Not tainted 2.6.32-504.16.2.el6.x86_64 #1
Call Trace:
 [<ffffffff8152971c>] ? panic+0xa7/0x16f
 [<ffffffff810ea046>] ? watchdog+0x246/0x250
 [<ffffffff810e9e00>] ? watchdog+0x0/0x250
 [<ffffffff8109e71e>] ? kthread+0x9e/0xc0
 [<ffffffff8100c20a>] ? child_rip+0xa/0x20
 [<ffffffff8109e680>] ? kthread+0x0/0xc0
 [<ffffffff8100c200>] ? child_rip+0x0/0x20