scsi: lpfc: Re-fix use after free in lpfc_rq_buf_free()

Commit 9816ef6ecbc1 ("scsi: lpfc: Use after free in lpfc_rq_buf_free()")
was made to correct a use after free condition in lpfc_rq_buf_free().
Unfortunately, a subsequent patch cut on a tree without the fix
inadvertently reverted the fix.

Put the fix back: Move the freeing of the rqb_entry to after the print
function that references it.

Link: https://lore.kernel.org/r/20201020202719.54726-4-james.smart@broadcom.com
Fixes: 411de511c694 ("scsi: lpfc: Fix RQ empty firmware trap")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/lpfc/lpfc_mem.c b/drivers/scsi/lpfc/lpfc_mem.c
index 79386e2..be54fbf 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_mem.c
+++ b/drivers/scsi/lpfc/lpfc_mem.c
@@ -721,7 +721,6 @@ lpfc_rq_buf_free(struct lpfc_hba *phba, struct lpfc_dmabuf *mp)
        drqe.address_hi = putPaddrHigh(rqb_entry->dbuf.phys);
        rc = lpfc_sli4_rq_put(rqb_entry->hrq, rqb_entry->drq, &hrqe, &drqe);
        if (rc < 0) {
-               (rqbp->rqb_free_buffer)(phba, rqb_entry);
                lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
                                "6409 Cannot post to HRQ %d: %x %x %x "
                                "DRQ %x %x\n",
@@ -731,6 +730,7 @@ lpfc_rq_buf_free(struct lpfc_hba *phba, struct lpfc_dmabuf *mp)
                                rqb_entry->hrq->entry_count,
                                rqb_entry->drq->host_index,
                                rqb_entry->drq->hba_index);
+               (rqbp->rqb_free_buffer)(phba, rqb_entry);
        } else {
                list_add_tail(&rqb_entry->hbuf.list, &rqbp->rqb_buffer_list);
                rqbp->buffer_count++;