[PATCH 3.16.y-ckt 065/144] target/pscsi: Fix NULL pointer dereference in get_device_type

[Luis Henriques]

3.16.7-ckt10 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicholas Bellinger <nab at linux-iscsi.org>

commit 215a8fe4198f607f34ecdbc9969dae783d8b5a61 upstream.

This patch fixes a NULL pointer dereference OOPs with pSCSI backends
within target_core_stat.c code.  The bug is caused by a configfs attr
read if no pscsi_dev_virt->pdv_sd has been configured.

Reported-by: Olaf Hering <olaf at aepfle.de>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/target/target_core_pscsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 94d00df28f39..7a986d401d3f 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1112,7 +1112,7 @@ static u32 pscsi_get_device_type(struct se_device *dev)
 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 	struct scsi_device *sd = pdv->pdv_sd;
 
-	return sd->type;
+	return (sd) ? sd->type : TYPE_NO_LUN;
 }
 
 static sector_t pscsi_get_blocks(struct se_device *dev)