scsi: lpfc: Fix list corruption detected in lpfc_put_sgl_per_hdwq

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>

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 6d89dd3dd532549c83511e626d141001e4fe2f0b..09e275e3bcd88b1f4c958d7c5e74ae8a0caab65c 100644 (file)
--- 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);
 }
 
 /**