Issue

• RHEL 6.6 kernel panics on SCSI host removal
• System reports NULL pointer dereference in scsi_remove_target() function of fc_wq_* kernel thread

BUG: unable to handle kernel NULL pointer dereference at 0000000000000288
IP: [<ffffffff8138de3a>] scsi_remove_target+0x8a/0x210
...
Pid: 569, comm: fc_wq_1 Not tainted 2.6.32-504.8.1.el6.x86_64 #1
...
RIP  [<ffffffff8138de3a>] scsi_remove_target+0x8a/0x210
 RSP <ffff881024e69dd0>
CR2: 0000000000000288

• System reports Watchdog detected hard LOCKUP on cpu X in scsi_remove_target() function of fc_wq_* kernel thread

Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 0
Pid: 795, comm: fc_wq_9 Tainted: P           ---------------    2.6.32-504.3.3.el6.x86_64 #1
Call Trace:
 <NMI>  [<ffffffff81529277>] ? panic+0xa7/0x16f
... 
 [<ffffffff810a4eae>] ? notify_die+0x2e/0x30
 [<ffffffff8152dcfb>] ? do_nmi+0x1bb/0x340
 [<ffffffff8152d5c0>] ? nmi+0x20/0x30
 [<ffffffff8138ddf3>] ? scsi_remove_target+0x93/0x210
 <<EOE>>  [<ffffffffa023b570>] ? fc_starget_delete+0x0/0x30 [scsi_transport_fc]
 [<ffffffffa023b596>] ? fc_starget_delete+0x26/0x30 [scsi_transport_fc]
...