From: James Smart <jsmart2021@xxxxxxxxx>
[ Upstream commit 807e7353d8a7105ce884d22b0dbc034993c6679c ]
Kernel is crashing with the following stacktrace:
BUG: unable to handle kernel NULL pointer dereference at
00000000000005bc
IP: lpfc_nvme_register_port+0x1a8/0x3a0 [lpfc]
...
Call Trace:
lpfc_nlp_state_cleanup+0x2b2/0x500 [lpfc]
lpfc_nlp_set_state+0xd7/0x1a0 [lpfc]
lpfc_cmpl_prli_prli_issue+0x1f7/0x450 [lpfc]
lpfc_disc_state_machine+0x7a/0x1e0 [lpfc]
lpfc_cmpl_els_prli+0x16f/0x1e0 [lpfc]
lpfc_sli_sp_handle_rspiocb+0x5b2/0x690 [lpfc]
lpfc_sli_handle_slow_ring_event_s4+0x182/0x230 [lpfc]
lpfc_do_work+0x87f/0x1570 [lpfc]
kthread+0x10d/0x130
ret_from_fork+0x35/0x40
During target side fault injections, it is possible to hit the
NLP_WAIT_FOR_UNREG case in lpfc_nvme_remoteport_delete. A prior commit
fixed a rebind and delete race condition, but called lpfc_nlp_put
unconditionally. This triggered a deletion and the crash.
Fix by movng nlp_put to inside the NLP_WAIT_FOR_UNREG case, where the nlp
will be being unregistered/removed. Leave the reference if the flag isn't
set.
Link: https://lore.kernel.org/r/20200322181304.37655-8-jsmart2021@xxxxxxxxx
Fixes: b15bd3e6212e ("scsi: lpfc: Fix nvme remoteport registration race conditions")
Signed-off-by: James Smart <jsmart2021@xxxxxxxxx>
Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/lpfc/lpfc_nvme.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c
index f6c8963c915d4..32b28651039e0 100644
--- a/drivers/scsi/lpfc/lpfc_nvme.c
+++ b/drivers/scsi/lpfc/lpfc_nvme.c
@@ -382,13 +382,15 @@ lpfc_nvme_remoteport_delete(struct nvme_fc_remote_port *remoteport)
if (ndlp->upcall_flags & NLP_WAIT_FOR_UNREG) {
ndlp->nrport = NULL;
ndlp->upcall_flags &= ~NLP_WAIT_FOR_UNREG;
- }
- spin_unlock_irq(&vport->phba->hbalock);
+ spin_unlock_irq(&vport->phba->hbalock);
- /* Remove original register reference. The host transport
- * won't reference this rport/remoteport any further.
- */
- lpfc_nlp_put(ndlp);
+ /* Remove original register reference. The host transport
+ * won't reference this rport/remoteport any further.
+ */
+ lpfc_nlp_put(ndlp);
+ } else {
+ spin_unlock_irq(&vport->phba->hbalock);
+ }
rport_err:
return;
--
2.20.1
