[PATCH 5.4 211/222] scsi: lpfc: Fix list corruption detected in lpfc_put_sgl_per_hdwq

Greg Kroah-Hartman
2020-01-22T13:27:47Z

From: James Smart <jsmart2021@gmail.com>

commit 35a635af54ce79881eb35ba20b64dcb1e81b0389 upstream.

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.")
Link: https://lore.kernel.org/r/20190922035906.10977-17-jsmart2021@gmail.com
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/lpfc/lpfc_sli.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -20108,6 +20108,13 @@ void lpfc_release_io_buf(struct lpfc_hba
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 */
@@ -20172,13 +20179,6 @@ void lpfc_release_io_buf(struct lpfc_hba
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);
}

/**