4.18-stable review patch. If anyone has any objections, please let me know.
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From: James Smart jsmart2021@gmail.com
[ 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@broadcom.com Signed-off-by: James Smart james.smart@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);