[PATCH 3.10 01/46] target: Fix left-over se_lun->lun_sep pointer OOPs

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Nicholas Bellinger <nab@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@gmx.de>
Tested-by: Sebastian Herbszt <herbszt@gmx.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/target/target_core_device.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -614,6 +614,7 @@ void core_dev_unexport(
 	dev->export_count--;
 	spin_unlock(&hba->device_lock);
 
+	lun->lun_sep = NULL;
 	lun->lun_se_dev = NULL;
 }