From: James Smart jsmart2021@gmail.com
[ 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@gmail.com Fixes: b15bd3e6212e ("scsi: lpfc: Fix nvme remoteport registration race conditions") Signed-off-by: James Smart jsmart2021@gmail.com Signed-off-by: Dick Kennedy dick.kennedy@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 f73726e55e44d..e3013858937b7 100644 --- a/drivers/scsi/lpfc/lpfc_nvme.c +++ b/drivers/scsi/lpfc/lpfc_nvme.c @@ -342,13 +342,15 @@ 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;