[PATCH 3.13 193/198] target: Fix left-over se_lun->lun_sep pointer OOPs

[Kamal Mostafa]

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

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

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

commit 83ff42fcce070801a3aa1cd6a3269d7426271a8d upstream.

This patch fixes a left-over se_lun->lun_sep pointer OOPs when one
of the /sys/kernel/config/target/$FABRIC/$WWPN/$TPGT/lun/$LUN/alua*
attributes is accessed after the $DEVICE symlink has been removed.

To address this bug, go ahead and clear se_lun->lun_sep memory in
core_dev_unexport(), so that the existing checks for show/store
ALUA attributes in target_core_fabric_configfs.c work as expected.

Reported-by: Sebastian Herbszt <herbszt at gmx.de>
Tested-by: Sebastian Herbszt <herbszt at gmx.de>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/target/target_core_device.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 8d27ba6..04e9288 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -616,6 +616,7 @@ void core_dev_unexport(
 	dev->export_count--;
 	spin_unlock(&hba->device_lock);
 
+	lun->lun_sep = NULL;
 	lun->lun_se_dev = NULL;
 }
 
-- 
1.9.1