4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: James Smart <jsmart2021@xxxxxxxxx>
[ Upstream commit 6871e8144f935a1f08e7fc6269c894861ce494aa ]
Kernel occasionally crashed with the following
ops on NVME Target:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
IP: [<ffffffffa042ee50>] lpfc_nvmet_defer_rcv+0x50/0x70 [lpfc]
Callback routine was called for deferred rcv when it should be treated as a
normal rcv.
Added code in callback routine to detect this condition and log a message,
then bail.
Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
Signed-off-by: James Smart <james.smart@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/lpfc/lpfc_nvmet.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -402,6 +402,7 @@ lpfc_nvmet_ctxbuf_post(struct lpfc_hba *
/* Process FCP command */
if (rc == 0) {
+ ctxp->rqb_buffer = NULL;
atomic_inc(&tgtp->rcv_fcp_cmd_out);
nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf);
return;
@@ -1116,8 +1117,17 @@ lpfc_nvmet_defer_rcv(struct nvmet_fc_tar
lpfc_nvmeio_data(phba, "NVMET DEFERRCV: xri x%x sz %d CPU %02x\n",
ctxp->oxid, ctxp->size, smp_processor_id());
+ if (!nvmebuf) {
+ lpfc_printf_log(phba, KERN_INFO, LOG_NVME_IOERR,
+ "6425 Defer rcv: no buffer xri x%x: "
+ "flg %x ste %x\n",
+ ctxp->oxid, ctxp->flag, ctxp->state);
+ return;
+ }
+
tgtp = phba->targetport->private;
- atomic_inc(&tgtp->rcv_fcp_cmd_defer);
+ if (tgtp)
+ atomic_inc(&tgtp->rcv_fcp_cmd_defer);
/* Free the nvmebuf since a new buffer already replaced it */
nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf);
