stable inclusion
from linux-4.19.167
commit fff1180d24e68d697f98642d71444316036a81ff
CVE: CVE-2020-28374

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

commit 2896c938 upstream.

When attempting to match EXTENDED COPY CSCD descriptors with corresponding
se_devices, target_xcopy_locate_se_dev_e4() currently iterates over LIO's
global devices list which includes all configured backstores.

This change ensures that only initiator-accessible backstores are
considered during CSCD descriptor lookup, according to the session's
se_node_acl LUN list.

To avoid LUN removal race conditions, device pinning is changed from being
configfs based to instead using the se_node_acl lun_ref.

Reference: CVE-2020-28374
Fixes: cbf031f4 ("target: Add support for EXTENDED_COPY copy offload emulation")
Reviewed-by: NLee Duncan <lduncan@suse.com>
Signed-off-by: NDavid Disseldorp <ddiss@suse.de>
Signed-off-by: NMike Christie <michael.christie@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>