From: Khazhismel Kumykov <khazhy@google.com>
Date: Thu, 13 Jul 2017 09:11:21 -0700
Subject: [PATCH] scsi: libiscsi: Fix use-after-free race during
 iscsi_session_teardown
References: bsc#1077989
Git-commit: 9e10b5121ad991ea6e84ca40b15a04cdc551bfe9
Patch-mainline: v4.14-rc4

Session attributes exposed through sysfs were freed before the device
was destroyed, resulting in a potential use-after-free. Free these
attributes after removing the device.

Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Acked-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/libiscsi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 51b446c8638f..0d416aacd8b9 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2873,9 +2873,6 @@ EXPORT_SYMBOL_GPL(iscsi_session_setup);
 /**
  * iscsi_session_teardown - destroy session, host, and cls_session
  * @cls_session: iscsi session
- *
- * The driver must have called iscsi_remove_session before
- * calling this.
  */
 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
 {
@@ -2885,6 +2882,8 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
 
 	iscsi_pool_free(&session->cmdpool);
 
+	iscsi_remove_session(cls_session);
+
 	kfree(session->password);
 	kfree(session->password_in);
 	kfree(session->username);
@@ -2899,7 +2898,8 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
 	kfree(session->portal_type);
 	kfree(session->discovery_parent_type);
 
-	iscsi_destroy_session(cls_session);
+	iscsi_free_session(cls_session);
+
 	iscsi_host_dec_session_cnt(shost);
 	module_put(owner);
 }
-- 
2.12.3