mainline inclusion
from mainline-5.1-rc1
commit a656183e
category: bugfix
bugzilla: 12855
CVE: NA

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

If there is an error queueing an iscsi command in iscsi_queuecommand(), for
example if the transport fails to take the command in
sessuin->tt->xmit_task(), then the error path can call
iscsi_complete_task() without first aquiring the back_lock as
required. This can lead to things like ITT pool can get corrupt, resulting
in duplicate ITTs being sent out.

The solution is to hold the back_lock around iscsi_complete_task() calls,
and to add a little commenting to help others understand when back_lock
must be held.
Signed-off-by: NLee Duncan <lduncan@suse.com>
Acked-by: NChris Leech <cleech@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Nzheng liang <zhengliang6@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>