scsi: qla2xxx: Fix unintialized List head crash

In case of IOCB Queue full or system where memory is low and driver
receives large number of RSCN storm, the stale sp pointer can stay on
gpnid_list resulting in page_fault.

This patch fixes this issue by initializing the sp->elem list head and
removing sp->elem before memory is freed.

Following stack trace is seen

 9 [ffff987b37d1bc60] page_fault at ffffffffad516768 [exception RIP: qla24xx_async_gpnid+496]
10 [ffff987b37d1bd10] qla24xx_async_gpnid at ffffffffc039866d [qla2xxx]
11 [ffff987b37d1bd80] qla2x00_do_work at ffffffffc036169c [qla2xxx]
12 [ffff987b37d1be38] qla2x00_do_dpc_all_vps at ffffffffc03adfed [qla2xxx]
13 [ffff987b37d1be78] qla2x00_do_dpc at ffffffffc036458a [qla2xxx]
14 [ffff987b37d1bec8] kthread at ffffffffacebae31

Fixes: 2d73ac6102d9 ("scsi: qla2xxx: Serialize GPNID for multiple RSCN")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_gs.c b/drivers/scsi/qla2xxx/qla_gs.c
index 2c35b0b2baa07f27211140fb0a7ea48b4cf8a7f4..7a3744006419589232322520594e635bdd247d36 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_gs.c
+++ b/drivers/scsi/qla2xxx/qla_gs.c
@@ -3708,6 +3708,10 @@ int qla24xx_async_gpnid(scsi_qla_host_t *vha, port_id_t *id)
        return rval;
 
 done_free_sp:
+       spin_lock_irqsave(&vha->hw->vport_slock, flags);
+       list_del(&sp->elem);
+       spin_unlock_irqrestore(&vha->hw->vport_slock, flags);
+
        if (sp->u.iocb_cmd.u.ctarg.req) {
                dma_free_coherent(&vha->hw->pdev->dev,
                        sizeof(struct ct_sns_pkt),

diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index 37ae0f6d8ae5743a182cc9fb963cbc868ddd925b..59fd5a9dfeb8703f437685fa7b4221419b42319e 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -222,6 +222,8 @@ qla2xxx_get_qpair_sp(struct qla_qpair *qpair, fc_port_t *fcport, gfp_t flag)
        sp->fcport = fcport;
        sp->iocbs = 1;
        sp->vha = qpair->vha;
+       INIT_LIST_HEAD(&sp->elem);
+
 done:
        if (!sp)
                QLA_QPAIR_MARK_NOT_BUSY(qpair);