From:   James Smart <jsmart2021@gmail.com>
To:     linux-scsi@vger.kernel.org
Cc:     James Smart <jsmart2021@gmail.com>,
        Dick Kennedy <dick.kennedy@broadcom.com>
Subject: [PATCH 16/20] lpfc: Fix list corruption detected in lpfc_put_sgl_per_hdwq
Date:   Sat, 21 Sep 2019 20:59:02 -0700
Message-Id: <20190922035906.10977-17-jsmart2021@gmail.com>
In-Reply-To: <20190922035906.10977-1-jsmart2021@gmail.com>
References: <20190922035906.10977-1-jsmart2021@gmail.com>
Sender: linux-scsi-owner@vger.kernel.org
Precedence: bulk

In lpfc_release_io_buf, an lpfc_io_buf is returned to the
'available' pool before any associated sgl or cmd and rsp
buffers are returned via their respective 'put' routines.
If xri rebalancing occurs and an lpfc_io_buf structure is
reused quickly, there may be a race condition between release
of old and association of new resources.

Re-ordered lpfc_release_io_buf to release sgl and cmd/rsp
buffer lists before releasing the lpfc_io_buf structure for re-use.

Fixes: d79c9e9d4b3d ("scsi: lpfc: Support dynamic unbounded SGL lists on G7 hardware.")
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
---
 drivers/scsi/lpfc/lpfc_sli.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 6d89dd3dd532..09e275e3bcd8 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -20138,6 +20138,13 @@ void lpfc_release_io_buf(struct lpfc_hba *phba, struct lpfc_io_buf *lpfc_ncmd,
 	lpfc_ncmd->cur_iocbq.wqe_cmpl = NULL;
 	lpfc_ncmd->cur_iocbq.iocb_cmpl = NULL;
 
+	if (phba->cfg_xpsgl && !phba->nvmet_support &&
+	    !list_empty(&lpfc_ncmd->dma_sgl_xtra_list))
+		lpfc_put_sgl_per_hdwq(phba, lpfc_ncmd);
+
+	if (!list_empty(&lpfc_ncmd->dma_cmd_rsp_list))
+		lpfc_put_cmd_rsp_buf_per_hdwq(phba, lpfc_ncmd);
+
 	if (phba->cfg_xri_rebalancing) {
 		if (lpfc_ncmd->expedite) {
 			/* Return to expedite pool */
@@ -20202,13 +20209,6 @@ void lpfc_release_io_buf(struct lpfc_hba *phba, struct lpfc_io_buf *lpfc_ncmd,
 		spin_unlock_irqrestore(&qp->io_buf_list_put_lock,
 				       iflag);
 	}
-
-	if (phba->cfg_xpsgl && !phba->nvmet_support &&
-	    !list_empty(&lpfc_ncmd->dma_sgl_xtra_list))
-		lpfc_put_sgl_per_hdwq(phba, lpfc_ncmd);
-
-	if (!list_empty(&lpfc_ncmd->dma_cmd_rsp_list))
-		lpfc_put_cmd_rsp_buf_per_hdwq(phba, lpfc_ncmd);
 }
 
 /**
-- 
2.13.7