NPIV enabled host crashed with NULL pointer dereference while executing 'scsi_softirq_done+0x22/0x150'

Issue

• NPIV enabled host crashed with NULL pointer dereference errors; this crash was occurred while doing following tests:

  • Configured a system with 2 Qlogic FC HBAs.
  • Configured 249 NPIV ports on each FC port.
  • Assigned the SAN devices to all 249 NPIV ports and started the IO.
  • When some of the target FC ports were manually disabled, the SCSI error handling process was triggered, but soon the NPIV host gets crashed with following error messages:

  Logs from system console:

  [41510.278952] qla2xxx [0000:04:00.0]-3821:9: Port to be marked lost on fcport=010200, current port state= LOST.
  [41510.278956] qla2xxx [0000:04:00.0]-3822:9: FCP command status: 0x29-0x0 (0xe0000) nexus=1:1:1 portid=010200 oxid=0x0 cdb=2a0000c2d3df00000800 len=0x1000 rsp_info=0x0 resid=0x0 fw_resid=0x0 sp=ffff880428309040 cp=ffff8803f4321f80.
  [41510.279378] BUG: unable to handle kernel NULL pointer dereference at 00000000000000c4
  [41510.279388] IP: [<ffffffff81420472>] scsi_softirq_done+0x22/0x150
  [41510.279391] PGD 35c21067 PUD 35c20067 PMD 0 
  [41510.279392] Oops: 0000 [#1] SMP 
  [...]
  [41510.279457] Stack:
  [41510.279464]  ffff880405d84e00 ffff880405d84d80 ffff88042fa03e80 ffffffff819430a0
  [41510.279468]  ffff88042fa03eb0 ffffffff812d16a0 ffff88042fa03e80 ffff88042fa03e80
  [41510.279471]  4b91c5db6999bcc1 0000000000000004 0000000000000004 0000000000000064
  [41510.279472] Call Trace:
  [41510.279475]  <IRQ> 
  [41510.279480]  [<ffffffff812d16a0>] blk_done_softirq+0x90/0xc0
  [41510.279485]  [<ffffffff81084b0f>] __do_softirq+0xef/0x280
  [41510.279491]  [<ffffffff8164721c>] call_softirq+0x1c/0x30
  [41510.279498]  [<ffffffff81016fc5>] do_softirq+0x65/0xa0
  [41510.279501]  [<ffffffff81084ea5>] irq_exit+0x115/0x120
  [41510.279504]  [<ffffffff81647db8>] do_IRQ+0x58/0xf0
  [41510.279508]  [<ffffffff8163d0ed>] common_interrupt+0x6d/0x6d
  [41510.279510]  <EOI> 
  [41510.279514]  [<ffffffff810b41c6>] ? finish_task_switch+0x56/0x170
  [41510.279517]  [<ffffffff8163a2b8>] __schedule+0x2d8/0x900
  [41510.279520]  [<ffffffff8163b9e9>] schedule_preempt_disabled+0x29/0x70
  [41510.279525]  [<ffffffff810d6244>] cpu_startup_entry+0x184/0x290
  [41510.279529]  [<ffffffff81624e07>] rest_init+0x77/0x80
  [41510.279535]  [<ffffffff81a8d057>] start_kernel+0x429/0x44a
  [41510.279538]  [<ffffffff81a8ca37>] ? repair_env_string+0x5c/0x5c
  [41510.279542]  [<ffffffff81a8c120>] ? early_idt_handlers+0x120/0x120
  [41510.279545]  [<ffffffff81a8c5ee>] x86_64_start_reservations+0x2a/0x2c
  [41510.279548]  [<ffffffff81a8c742>] x86_64_start_kernel+0x152/0x175
  [41510.279570] Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 48 8b 9f 00 01 00 00 44 8b af 60 01 00 00 48 8d 43 18 <44> 8b b3 c4 00 00 00 48 8b 13 48 89 43 18 48 89 43 20 f0 ff 82 
  [41510.279573] RIP  [<ffffffff81420472>] scsi_softirq_done+0x22/0x150
  [41510.279574]  RSP <ffff88042fa03e50>
  [41510.279574] CR2: 00000000000000c4