target: Fix left-over se_lun->lun_sep pointer OOPs

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>

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 8032917b663671b058eaa1e05c4eac62d307f667..68398753eb826b65b92aa5e1a0eddbf1e1e3775e 100644 (file)
--- 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;
 }