[PATCH v2 02/21] lpfc: fix pci hot plug crash in list_add call

James Smart
2017-09-30T00:34:58Z

During pci hot plug, the kernel crashes in a list_add_call

The lookup by tag function will return null if the IOCB is out of
range or does not have the on txcmplq flag set.

Fix: Check for null return from lookup by tag.

Cc: <stable@vger.kernel.org> # 4.12+
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>

---
v2: original v1 hot plug patch split into 2 patches

drivers/scsi/lpfc/lpfc_sli.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 8b119f87b51d..b8513c1adcef 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -12507,19 +12507,21 @@ lpfc_sli4_els_wcqe_to_rspiocbq(struct lpfc_hba *phba,
/* Look up the ELS command IOCB and create pseudo response IOCB */
cmdiocbq = lpfc_sli_iocbq_lookup_by_tag(phba, pring,
bf_get(lpfc_wcqe_c_request_tag, wcqe));
- /* Put the iocb back on the txcmplq */
- lpfc_sli_ringtxcmpl_put(phba, pring, cmdiocbq);
- spin_unlock_irqrestore(&pring->ring_lock, iflags);
-
if (unlikely(!cmdiocbq)) {
+ spin_unlock_irqrestore(&pring->ring_lock, iflags);
lpfc_printf_log(phba, KERN_WARNING, LOG_SLI,
"0386 ELS complete with no corresponding "
- "cmdiocb: iotag (%d)\n",
- bf_get(lpfc_wcqe_c_request_tag, wcqe));
+ "cmdiocb: 0x%x 0x%x 0x%x 0x%x\n",
+ wcqe->word0, wcqe->total_data_placed,
+ wcqe->parameter, wcqe->word3);
lpfc_sli_release_iocbq(phba, irspiocbq);
return NULL;
}

+ /* Put the iocb back on the txcmplq */
+ lpfc_sli_ringtxcmpl_put(phba, pring, cmdiocbq);
+ spin_unlock_irqrestore(&pring->ring_lock, iflags);
+
/* Fake the irspiocbq and copy necessary response information */
lpfc_sli4_iocb_param_transfer(phba, irspiocbq, cmdiocbq, wcqe);

@@ -17137,7 +17139,8 @@ lpfc_sli4_handle_mds_loopback(struct lpfc_vport *vport,
if (pcmd && pcmd->virt)
dma_pool_free(phba->lpfc_drb_pool, pcmd->virt, pcmd->phys);
kfree(pcmd);
- lpfc_sli_release_iocbq(phba, iocbq);
+ if (iocbq)
+ lpfc_sli_release_iocbq(phba, iocbq);
lpfc_in_buf_free(phba, &dmabuf->dbuf);
}

--
2.13.1