From: James Smart Date: Tue, 12 Mar 2019 23:30:06 +0000 (-0700) Subject: scsi: lpfc: Fix use-after-free mailbox cmd completion X-Git-Tag: v5.4-rc1~699^2~294 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9b1640686470fbbd1c6efb35ada6fe1427ea8d0f;p=platform%2Fkernel%2Flinux-rpi.git scsi: lpfc: Fix use-after-free mailbox cmd completion When unloading the driver, mailbox commands may be sent without holding a reference on the ndlp. By the time the mailbox command completes, the ndlp may have reduced its ref counts and been freed. The problem was reported by KASAN. While unregistering due to driver unload, have the completion noop'd by setting the ndlp context NULL'd. Due to the unload, no further action was necessary. Also, while reviewing this path, the generic nulling of the context after handling should be slightly moved. Reported by: Bart Van Assche Signed-off-by: Dick Kennedy Signed-off-by: James Smart Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c index aa4961a..3fb20ad 100644 --- a/drivers/scsi/lpfc/lpfc_hbadisc.c +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c @@ -4868,6 +4868,10 @@ lpfc_unreg_rpi(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp) * accept PLOGIs after unreg_rpi_cmpl */ acc_plogi = 0; + } else if (vport->load_flag & FC_UNLOADING) { + mbox->ctx_ndlp = NULL; + mbox->mbox_cmpl = + lpfc_sli_def_mbox_cmpl; } else { mbox->ctx_ndlp = ndlp; mbox->mbox_cmpl = diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 57b4a46..de5715b 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -2502,8 +2502,8 @@ lpfc_sli_def_mbox_cmpl(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb) } else { ndlp->nlp_flag &= ~NLP_UNREG_INP; } + pmb->ctx_ndlp = NULL; } - pmb->ctx_ndlp = NULL; } /* Check security permission status on INIT_LINK mailbox command */