From e7f4034912d08a5fdfd7bdbcf9e86e885de1de21 Mon Sep 17 00:00:00 2001 From: James Smart Date: Sun, 22 Mar 2020 11:12:55 -0700 Subject: [PATCH] scsi: lpfc: Fix lpfc overwrite of sg_cnt field in nvmefc_tgt_fcp_req In lpfc_nvmet_prep_fcp_wqe() the line "rsp->sg_cnt = 0" is modifying the transport's data structure. This may result in the transport believing the s/g list was already freed, thus may not unmap/free it properly. Lpfc driver should not modify the transport data structure. The zeroing of the sg_cnt is to avoid use of the transport's sgl in a subsequent loop where the driver builds the necessary requests for the adapter firmware to complete the IO. Change LLDD to use a local copy of the transport sg_cnt when building requests to be passed to the adapter fw. Link: https://lore.kernel.org/r/20200322181304.37655-4-jsmart2021@gmail.com Signed-off-by: James Smart Signed-off-by: Dick Kennedy Signed-off-by: Martin K. Petersen --- drivers/scsi/lpfc/lpfc_nvmet.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c index 9dc9afe1c255..ae89d1450912 100644 --- a/drivers/scsi/lpfc/lpfc_nvmet.c +++ b/drivers/scsi/lpfc/lpfc_nvmet.c @@ -2598,7 +2598,7 @@ lpfc_nvmet_prep_fcp_wqe(struct lpfc_hba *phba, union lpfc_wqe128 *wqe; struct ulp_bde64 *bde; dma_addr_t physaddr; - int i, cnt; + int i, cnt, nsegs; int do_pbde; int xc = 1; @@ -2629,6 +2629,7 @@ lpfc_nvmet_prep_fcp_wqe(struct lpfc_hba *phba, phba->cfg_nvme_seg_cnt); return NULL; } + nsegs = rsp->sg_cnt; tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private; nvmewqe = ctxp->wqeq; @@ -2868,7 +2869,7 @@ lpfc_nvmet_prep_fcp_wqe(struct lpfc_hba *phba, wqe->fcp_trsp.rsvd_12_15[0] = 0; /* Use rspbuf, NOT sg list */ - rsp->sg_cnt = 0; + nsegs = 0; sgl->word2 = 0; atomic_inc(&tgtp->xmt_fcp_rsp); break; @@ -2885,7 +2886,7 @@ lpfc_nvmet_prep_fcp_wqe(struct lpfc_hba *phba, nvmewqe->drvrTimeout = (phba->fc_ratov * 3) + LPFC_DRVR_TIMEOUT; nvmewqe->context1 = ndlp; - for_each_sg(rsp->sg, sgel, rsp->sg_cnt, i) { + for_each_sg(rsp->sg, sgel, nsegs, i) { physaddr = sg_dma_address(sgel); cnt = sg_dma_len(sgel); sgl->addr_hi = putPaddrHigh(physaddr);