[PATCH 6/8] lpfc: Fix link down processing to address NULL pointer dereference

James Smart
2021-10-20T21:14:38Z

If an FC link down transition while PLOGIs are outstanding to
fabric well known addresses, outstanding ABTS requests may result
in a NULL pointer dereference. Driver unload requests may hang with
repeated "2878" log messages.

The Link down processing results in ABTS requests for outstanding ELS
requests. The Abort WQEs are sent for the ELS's before the driver had
set the link state to down. Thus the driver is sending the Abort with
the expectation that an ABTS will be sent on the wire. The Abort
request is stalled waiting for the link to come up. In some conditions
the driver may auto-complete the ELS's thus if the link does come up,
the Abort completions may reference an invalid structure.

Fix by ensuring that Abort set the flag to avoid link traffic if
issued due to conditions where the link failed.

Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
---
drivers/scsi/lpfc/lpfc_sli.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index f82f809617a0..5dedb3de271d 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -12403,17 +12403,17 @@ lpfc_sli_issue_abort_iotag(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,

/* ABTS WQE must go to the same WQ as the WQE to be aborted */
abtsiocbp->hba_wqidx = cmdiocb->hba_wqidx;
- if (cmdiocb->iocb_flag & LPFC_IO_FCP) {
- abtsiocbp->iocb_flag |= LPFC_IO_FCP;
- abtsiocbp->iocb_flag |= LPFC_USE_FCPWQIDX;
- }
+ if (cmdiocb->iocb_flag & LPFC_IO_FCP)
+ abtsiocbp->iocb_flag |= (LPFC_IO_FCP | LPFC_USE_FCPWQIDX);
if (cmdiocb->iocb_flag & LPFC_IO_FOF)
abtsiocbp->iocb_flag |= LPFC_IO_FOF;

- if (phba->link_state >= LPFC_LINK_UP)
- iabt->ulpCommand = CMD_ABORT_XRI_CN;
- else
+ if (phba->link_state < LPFC_LINK_UP ||
+ (phba->sli_rev == LPFC_SLI_REV4 &&
+ phba->sli4_hba.link_state.status == LPFC_FC_LA_TYPE_LINK_DOWN))
iabt->ulpCommand = CMD_CLOSE_XRI_CN;
+ else
+ iabt->ulpCommand = CMD_ABORT_XRI_CN;

if (cmpl)
abtsiocbp->iocb_cmpl = cmpl;
--
2.26.2